Merge current main and make purchase filing atomic under concurrent writes

core/Cargo.lock

@@ -104,7 +104,7 @@ dependencies = [
 
 [[package]]
 name = "archipelago"
-version = "1.8.19-alpha"
+version = "1.8.21-alpha"
 dependencies = [
  "anyhow",
  "archipelago-container",

core/archipelago/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "archipelago"
-version = "1.8.19-alpha"
+version = "1.8.21-alpha"
 edition = "2021"
 license.workspace = true
 description = "Archipelago Bitcoin Node OS - Native backend"

core/archipelago/src/api/handler/proxy.rs

@@ -138,6 +138,19 @@ impl ApiHandler {
         cors_origin: &str,
     ) -> Result<Response<hyper::Body>> {
         let suffix = path.strip_prefix("/proxy/lnd").unwrap_or("/");
+        if suffix == "/archy-status" {
+            return Ok(Response::builder()
+                .status(StatusCode::OK)
+                .header("Content-Type", "application/json")
+                .header("Cache-Control", "no-store")
+                .header("Access-Control-Allow-Origin", cors_origin)
+                .header("Access-Control-Allow-Credentials", "true")
+                .header("Vary", "Origin")
+                .body(hyper::Body::from(
+                    rpc.handle_lnd_readiness().await.to_string(),
+                ))?);
+        }
+
         let url = format!("{LND_REST_BASE_URL}{suffix}");
         // LND REST serves a self-signed cert and requires the admin macaroon.
         // A bare reqwest::get() uses the default client, which rejects the

core/archipelago/src/api/rpc/content.rs

@@ -22,9 +22,9 @@ const FILE_CATALOG_PROTOCOL: &str = "https://archipelago.dev/protocols/file-cata
 /// Best-effort reclaim of an ecash payment token that was minted but the sale
 /// didn't complete (seller unreachable or couldn't redeem it), so the buyer
 /// doesn't lose the value. For Fedimint the spender can reissue its own
-/// un-redeemed notes; for Cashu the proofs are received back. Fails silently if
-/// the seller already claimed the token (then the value is genuinely gone).
-async fn reclaim_spent_ecash(data_dir: &std::path::Path, token: &str, backend: &str) {
+/// un-redeemed notes; for Cashu the proofs are received back. Report the actual
+/// recovered amount, or explicitly say when a refund could not be confirmed.
+async fn reclaim_spent_ecash(data_dir: &std::path::Path, token: &str, backend: &str) -> String {
     let res = match backend {
         "fedimint" => crate::wallet::fedimint_client::reissue_into_any(data_dir, token)
             .await
@@ -32,16 +32,62 @@ async fn reclaim_spent_ecash(data_dir: &std::path::Path, token: &str, backend: &
         _ => ecash::receive_token(data_dir, token).await,
     };
     match res {
-        Ok(sats) => tracing::info!(
-            "paid download: reclaimed {sats} sats of unspent {backend} ecash after a failed sale"
-        ),
-        Err(e) => tracing::warn!(
-            "paid download: could not reclaim {backend} ecash (the peer may have already \
-             claimed it): {e:#}"
-        ),
+        Ok(sats) => {
+            tracing::info!("paid download: reclaimed {sats} sats after failed sale");
+            format!("Refunded {sats} sats to your wallet.")
+        }
+        Err(e) => {
+            tracing::warn!("paid download: refund not confirmed: {e}");
+            "Your refund could not be confirmed. The seller may have received the payment. Do not pay again until this is checked.".to_string()
+        }
     }
 }
 
+/// Keep first purchases and cached repeats compatible with both existing clients.
+fn paid_content_response(bytes: &[u8], mime: &str, paid_sats: u64) -> serde_json::Value {
+    use base64::Engine;
+    let data = base64::engine::general_purpose::STANDARD.encode(bytes);
+    serde_json::json!({
+        "data": data, "data_base64": data,
+        "size": bytes.len(), "size_bytes": bytes.len(),
+        "mime_type": mime, "paid_sats": paid_sats, "owned": true,
+    })
+}
+
+/// File purchases through an atomic no-clobber write in Files' own namespace.
+async fn file_purchase_in_files(
+    data_dir: &std::path::Path,
+    filename: &str,
+    mime: &str,
+    bytes: &[u8],
+) -> Result<String> {
+    let folder = if mime.starts_with("image/") || mime.starts_with("video/") {
+        "Photos"
+    } else if mime.starts_with("audio/") {
+        "Music"
+    } else {
+        "Documents"
+    };
+    let root = data_dir.join("filebrowser");
+    anyhow::ensure!(
+        tokio::fs::metadata(&root).await?.is_dir(),
+        "Files storage is unavailable"
+    );
+    let name = std::path::Path::new(filename)
+        .file_name()
+        .and_then(|n| n.to_str())
+        .filter(|n| !n.is_empty())
+        .unwrap_or("download");
+    let path =
+        crate::container::filebrowser::save_new_file(&root.join(folder), name, bytes).await?;
+    Ok(format!(
+        "{folder}/{}",
+        path.file_name()
+            .and_then(|n| n.to_str())
+            .context("Invalid Files name")?
+    ))
+}
+
 impl RpcHandler {
     /// List content I'm sharing.
     pub(super) async fn handle_content_list_mine(&self) -> Result<serde_json::Value> {
@@ -463,17 +509,10 @@ impl RpcHandler {
                     crate::content_owned::read_owned(&self.config.data_dir, &o.onion, &o.content_id)
                         .await
                 {
-                    use base64::Engine;
-                    return Ok(serde_json::json!({
-                        "owned": true,
-                        "already_owned": true,
-                        "filename": o.filename,
-                        "mime_type": mime,
-                        "size_bytes": bytes.len(),
-                        "paid_sats": 0,
-                        "data_base64":
-                            base64::engine::general_purpose::STANDARD.encode(&bytes),
-                    }));
+                    let mut result = paid_content_response(&bytes, &mime, 0);
+                    result["already_owned"] = serde_json::json!(true);
+                    result["filename"] = serde_json::json!(o.filename);
+                    return Ok(result);
                 }
                 // Cache record exists but bytes are gone — fall through and
                 // repurchase rather than stranding the user.
@@ -547,29 +586,27 @@ impl RpcHandler {
         // Surface a real reason instead of the generic sanitized error (#30):
         // the dial already tries FIPS/mesh then falls back to Tor, so a failure
         // here means the peer is genuinely unreachable on both transports.
-        let (response, transport) = match crate::fips::dial::PeerRequest::new(
-            fips_npub.as_deref(),
-            onion,
-            &path,
-        )
-        .service(crate::settings::transport::PeerService::PeerFiles)
-        .header("X-Federation-DID", local_did)
-        .header("X-Payment-Token", token_str.clone())
-        .timeout(std::time::Duration::from_secs(900))
-        .send_get()
-        .await
-        {
-            Ok(v) => v,
-            Err(e) => {
-                tracing::warn!("paid peer download dial failed for {}: {:#}", onion, e);
-                // The token was already minted/spent — reclaim it so the buyer
-                // doesn't lose the value when the seller was simply unreachable.
-                reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
-                return Ok(serde_json::json!({
-                    "error": "Could not reach the peer over mesh or Tor — it may be offline. Your ecash was refunded to your wallet. Please try again."
-                }));
-            }
-        };
+        let (response, transport) =
+            match crate::fips::dial::PeerRequest::new(fips_npub.as_deref(), onion, &path)
+                .service(crate::settings::transport::PeerService::PeerFiles)
+                .header("X-Federation-DID", local_did)
+                .header("X-Payment-Token", token_str.clone())
+                .timeout(std::time::Duration::from_secs(900))
+                .send_get()
+                .await
+            {
+                Ok(v) => v,
+                Err(e) => {
+                    tracing::warn!("paid peer download dial failed for {}: {:#}", onion, e);
+                    // The token was already minted/spent — reclaim it so the buyer
+                    // doesn't lose the value when the seller was simply unreachable.
+                    let refund =
+                        reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
+                    return Ok(serde_json::json!({
+                        "error": format!("Could not reach the peer over mesh or Tor. {refund}")
+                    }));
+                }
+            };
         // Record which transport actually reached the peer (B14).
         if let Err(e) = crate::federation::record_peer_transport(
             &self.config.data_dir,
@@ -583,25 +620,17 @@ impl RpcHandler {
         }
 
         if response.status() == reqwest::StatusCode::PAYMENT_REQUIRED {
-            // Payment was rejected by the seller. Surface the most likely cause
-            // per backend — for ecash both sides must share a redemption network
-            // (a Cashu mint, or a Fedimint federation).
+            // A 402 can mean mint validation, network failure, underpayment,
+            // or an unaccepted mint. Do not invent a mint-mismatch diagnosis.
             let body = response.text().await.unwrap_or_default();
             tracing::warn!(
                 "paid download: seller {onion} rejected {used_backend} payment of {price_sats} sats: {body}"
             );
             // Seller couldn't redeem the token — reclaim it so the buyer keeps
             // their funds (the spent-but-unredeemed-notes case the user hit).
-            reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
-            let hint = match used_backend {
-                "fedimint" => "the seller isn't in the same Fedimint federation as you",
-                _ => "the seller doesn't accept your Cashu mint",
-            };
+            let refund = reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
             return Ok(serde_json::json!({
-                "error": format!(
-                    "Payment rejected by the seller — {hint}. Your ecash was refunded to \
-                     your wallet. Try the other ecash type, or use a shared mint/federation."
-                )
+                "error": format!("The seller could not verify the payment. {refund}")
             }));
         }
 
@@ -609,9 +638,9 @@ impl RpcHandler {
             let status = response.status();
             let body = response.text().await.unwrap_or_default();
             tracing::warn!("paid download: seller {onion} returned {status}: {body}");
-            reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
+            let refund = reclaim_spent_ecash(&self.config.data_dir, &token_str, used_backend).await;
             return Ok(serde_json::json!({
-                "error": format!("Peer returned an error ({status}). Your ecash was refunded to your wallet.")
+                "error": format!("Peer returned an error ({status}). {refund}")
             }));
         }
 
@@ -658,47 +687,21 @@ impl RpcHandler {
             tracing::warn!("paid download: failed to cache purchased content (non-fatal): {e:#}");
         }
 
-        // Auto-file the purchase into the user's Files area (2026-07-22):
-        // Photos for images/video, Music for audio, Documents otherwise —
-        // same buckets the Cloud view uses. The in-app viewer still plays
-        // from the purchase cache; this makes the file ALSO show up where
-        // files live, on every device, without relying on a browser
-        // download. Best-effort: never fail a paid download over it.
-        {
-            let folder = if mime_type.starts_with("image/") || mime_type.starts_with("video/") {
-                "Photos"
-            } else if mime_type.starts_with("audio/") {
-                "Music"
-            } else {
-                "Documents"
-            };
-            let base = std::path::Path::new(&filename)
-                .file_name()
-                .and_then(|n| n.to_str())
-                .unwrap_or("download")
-                .to_string();
-            let dir = self.config.data_dir.join("filebrowser").join(folder);
-            match crate::container::filebrowser::save_new_file(&dir, &base, &bytes).await {
-                Ok(path) => tracing::info!("paid download: filed into {}", path.display()),
-                Err(e) => tracing::warn!(
-                    "paid download: filing into {} failed (non-fatal): {e:#}",
-                    dir.display()
-                ),
-            }
+        // The durable purchased-content cache above is primary. A Files copy
+        // remains optional: a stopped FileBrowser must not undo a paid download.
+        let filed =
+            file_purchase_in_files(&self.config.data_dir, &filename, &mime_type, &bytes).await;
+        match filed {
+            Ok(path) => tracing::info!("paid download: filed into Files/{path}"),
+            Err(error) => tracing::warn!(
+                "paid download: optional Files copy failed; purchase cache retained: {error}"
+            ),
         }
 
-        use base64::Engine;
-        let encoded = base64::engine::general_purpose::STANDARD.encode(&bytes);
-
         tracing::info!("paid download: received {} bytes from {onion} (paid {price_sats} sats via {used_backend})", bytes.len());
-        Ok(serde_json::json!({
-            "data": encoded,
-            "size": bytes.len(),
-            "paid_sats": price_sats,
-            "ecash_backend": used_backend,
-            "mime_type": mime_type,
-            "owned": true,
-        }))
+        let mut result = paid_content_response(&bytes, &mime_type, price_sats);
+        result["ecash_backend"] = serde_json::json!(used_backend);
+        Ok(result)
     }
 
     /// Buyer side (#46): ask the selling node to mint a Lightning invoice for a
@@ -1371,3 +1374,7 @@ impl RpcHandler {
         }
     }
 }
+
+#[cfg(test)]
+#[path = "content_tests.rs"]
+mod tests;

core/archipelago/src/api/rpc/content_tests.rs

@@ -0,0 +1,56 @@
+use super::*;
+
+#[test]
+fn first_and_cached_paid_downloads_have_the_same_client_payload_contract() {
+    use base64::Engine;
+    for paid in [0, 1] {
+        let response = paid_content_response(&[0, 255, 123], "application/octet-stream", paid);
+        assert_eq!(response["data"], response["data_base64"]);
+        assert_eq!(
+            base64::engine::general_purpose::STANDARD
+                .decode(response["data"].as_str().unwrap())
+                .unwrap(),
+            [0, 255, 123]
+        );
+        assert_eq!(response["size"], 3);
+        assert_eq!(response["size_bytes"], 3);
+        assert_eq!(response["paid_sats"], paid);
+        assert_eq!(response["owned"], true);
+    }
+}
+
+#[tokio::test]
+async fn files_copy_routes_media_and_sanitizes_the_filename() {
+    let dir = tempfile::tempdir().unwrap();
+    tokio::fs::create_dir(dir.path().join("filebrowser"))
+        .await
+        .unwrap();
+    for (mime, folder) in [
+        ("image/png", "Photos"),
+        ("video/mp4", "Photos"),
+        ("audio/mpeg", "Music"),
+        ("text/plain", "Documents"),
+    ] {
+        let relative = file_purchase_in_files(dir.path(), "../name #?.bin", mime, b"paid")
+            .await
+            .unwrap();
+        assert!(relative.starts_with(&format!("{folder}/name #?")));
+        assert_eq!(
+            tokio::fs::read(dir.path().join("filebrowser").join(relative))
+                .await
+                .unwrap(),
+            b"paid"
+        );
+    }
+}
+
+#[tokio::test]
+async fn unavailable_files_storage_is_reported_without_creating_a_fake_installation() {
+    let dir = tempfile::tempdir().unwrap();
+    assert!(
+        file_purchase_in_files(dir.path(), "name", "text/plain", b"bytes")
+            .await
+            .is_err()
+    );
+    assert!(!dir.path().join("filebrowser").exists());
+}

core/archipelago/src/api/rpc/lnd/info.rs

@@ -109,7 +109,50 @@ fn checked_balances(
     ))
 }
 
+fn bitcoin_wait_state(
+    installed: bool,
+    running: bool,
+    fresh: bool,
+    ibd: Option<bool>,
+) -> (&'static str, &'static str) {
+    if !installed {
+        ("waiting_install", "Waiting for Bitcoin to be installed")
+    } else if !running {
+        ("waiting_start", "Waiting for Bitcoin to start")
+    } else if !fresh || ibd.is_none() {
+        ("waiting_start", "Waiting for Bitcoin to start")
+    } else if ibd == Some(true) {
+        ("waiting_sync", "Waiting for Bitcoin to sync")
+    } else {
+        ("bitcoin_ready", "Bitcoin is ready")
+    }
+}
+
 impl RpcHandler {
+    pub(crate) async fn handle_lnd_readiness(&self) -> serde_json::Value {
+        let (data, _) = self.state_manager.get_snapshot().await;
+        if !data.server_info.status_info.containers_scanned {
+            return serde_json::json!({"state":"checking", "message":"Checking Bitcoin availability"});
+        }
+        let nodes: Vec<_> = ["bitcoin-core", "bitcoin-knots", "bitcoin"]
+            .iter()
+            .filter_map(|id| data.package_data.get(*id))
+            .collect();
+        let installed = !nodes.is_empty();
+        let running = nodes
+            .iter()
+            .any(|p| p.state == crate::data_model::PackageState::Running);
+        let bitcoin = crate::bitcoin_status::get_bitcoin_status().await;
+        let ibd = bitcoin
+            .blockchain_info
+            .as_ref()
+            .and_then(|v| v.get("initialblockdownload"))
+            .and_then(|v| v.as_bool());
+        let (state, message) =
+            bitcoin_wait_state(installed, running, bitcoin.ok && !bitcoin.stale, ibd);
+        serde_json::json!({"state": state, "message": message})
+    }
+
     pub(in crate::api::rpc) async fn handle_lnd_getinfo(&self) -> Result<serde_json::Value> {
         let macaroon_bytes = read_lnd_admin_macaroon().await?;
         let macaroon_hex = hex::encode(&macaroon_bytes);
@@ -419,3 +462,44 @@ mod tests {
         assert!(!is_valid_identity_pubkey(&"g".repeat(66)));
     }
 }
+
+#[cfg(test)]
+mod dependency_readiness_tests {
+    use super::bitcoin_wait_state;
+    #[test]
+    fn waiting_states_cover_install_start_sync_outage_and_recovery() {
+        assert_eq!(
+            bitcoin_wait_state(false, false, false, None).0,
+            "waiting_install"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, false, false, None).0,
+            "waiting_start"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, true, false, None).0,
+            "waiting_start"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, true, true, Some(true)).0,
+            "waiting_sync"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, true, true, Some(false)).0,
+            "bitcoin_ready"
+        );
+        // Previously synced cached information must not hide a current outage.
+        assert_eq!(
+            bitcoin_wait_state(true, true, false, Some(false)).0,
+            "waiting_start"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, true, true, None).0,
+            "waiting_start"
+        );
+        assert_eq!(
+            bitcoin_wait_state(true, true, true, Some(false)).0,
+            "bitcoin_ready"
+        );
+    }
+}

core/archipelago/src/api/rpc/lnd/mod.rs

@@ -133,12 +133,36 @@ async fn stream_lnd_transactions(sm: &crate::state::StateManager) -> Result<()>
 /// RPC-unreachable and locked-wallet states are deliberately NOT handled
 /// here — container-down is crash-recovery's job, and unlocking needs the
 /// operator.
+fn bitcoin_ready_for_lnd_watchdog(status: &crate::bitcoin_status::BitcoinNodeStatus) -> bool {
+    status.ok
+        && !status.stale
+        && status.age_ms < 30_000
+        && status
+            .blockchain_info
+            .as_ref()
+            .and_then(|v| v.get("initialblockdownload"))
+            .and_then(|v| v.as_bool())
+            == Some(false)
+}
+
 pub(crate) fn spawn_lnd_health_watchdog() {
     tokio::spawn(async move {
         let mut bad_minutes: u32 = 0;
         let mut last_restart: Option<tokio::time::Instant> = None;
+        let mut last_height: Option<u64> = None;
         loop {
             tokio::time::sleep(std::time::Duration::from_secs(60)).await;
+            // Initial Bitcoin sync, warmup, and outages are dependencies to
+            // wait for, never evidence that LND is wedged. Do not accumulate
+            // restart pressure during a days-long initial block download.
+            let bitcoin = crate::bitcoin_status::get_bitcoin_status().await;
+            if !bitcoin_ready_for_lnd_watchdog(&bitcoin)
+                || crate::app_ops::lifecycle_op_in_flight("lnd")
+            {
+                bad_minutes = 0;
+                last_height = None;
+                continue;
+            }
             let Ok(bytes) = read_lnd_admin_macaroon().await else {
                 bad_minutes = 0; // no LND on this node (or not set up yet)
                 continue;
@@ -161,6 +185,10 @@ pub(crate) fn spawn_lnd_health_watchdog() {
                 bad_minutes = 0; // down/locked — not the wedge signature
                 continue;
             };
+            if !resp.status().is_success() {
+                bad_minutes = 0;
+                continue;
+            }
             let Ok(info) = resp.json::<serde_json::Value>().await else {
                 bad_minutes = 0;
                 continue;
@@ -182,7 +210,12 @@ pub(crate) fn spawn_lnd_health_watchdog() {
                     .get("num_pending_channels")
                     .and_then(|v| v.as_u64())
                     .unwrap_or(0);
-            let wedged = !synced || (channels > 0 && peers == 0);
+            let height = info.get("block_height").and_then(|v| v.as_u64());
+            let progressing = height
+                .zip(last_height)
+                .is_some_and(|(now, before)| now > before);
+            last_height = height;
+            let wedged = !progressing && (!synced || (channels > 0 && peers == 0));
             if !wedged {
                 bad_minutes = 0;
                 continue;
@@ -239,3 +272,31 @@ impl RpcHandler {
         Ok((client, macaroon_hex))
     }
 }
+
+#[cfg(test)]
+mod watchdog_dependency_tests {
+    use super::bitcoin_ready_for_lnd_watchdog;
+    use crate::bitcoin_status::BitcoinNodeStatus;
+    use serde_json::json;
+    #[test]
+    fn initial_sync_warmup_outage_stale_and_unknown_never_trigger_lnd_restart() {
+        let mut status = BitcoinNodeStatus::default();
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+        status.ok = true;
+        status.blockchain_info = Some(json!({"initialblockdownload":true}));
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+        status.blockchain_info = Some(json!({"initialblockdownload":false}));
+        assert!(bitcoin_ready_for_lnd_watchdog(&status));
+        status.stale = true;
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+        status.stale = false;
+        status.ok = false;
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+        status.ok = true;
+        status.age_ms = 30_000;
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+        status.age_ms = 0;
+        status.blockchain_info = Some(json!({}));
+        assert!(!bitcoin_ready_for_lnd_watchdog(&status));
+    }
+}

core/archipelago/src/api/rpc/package/install.rs

@@ -326,6 +326,10 @@ impl RpcHandler {
         // an older version pins it so install_fresh resolves that image and the
         // update badge stays suppressed. See docs/bitcoin-multi-version-design.md.
         if matches!(package_id, "bitcoin-core" | "bitcoin-knots") {
+            if let Some(value) = params.get("prune") {
+                let prune = value.as_bool().context("prune must be a boolean")?;
+                crate::settings::bitcoin_storage::save(&self.config.data_dir, prune).await?;
+            }
             if let Some(version) = params.get("version").and_then(|v| v.as_str()) {
                 persist_install_version_selection(package_id, version).await;
             }

core/archipelago/src/api/rpc/package/set_config.rs

@@ -153,8 +153,18 @@ impl RpcHandler {
         let default = app_catalog::catalog_default_version(app_id);
         let cfg = version_config::read(app_id);
         let installed = installed_version(app_id).await;
+        let bitcoin_prune = if matches!(app_id, "bitcoin-core" | "bitcoin-knots") {
+            Some(
+                crate::settings::bitcoin_storage::load(&self.config.data_dir)
+                    .await?
+                    .prune,
+            )
+        } else {
+            None
+        };
 
         Ok(serde_json::json!({
+            "bitcoinPrune": bitcoin_prune,
             "id": app_id,
             "supportsVersions": supports_versions(app_id),
             "default": default,

core/archipelago/src/bitcoin_status.rs

@@ -100,7 +100,11 @@ fn friendly_transient_error(has_cached_state: bool, err_msg: &str) -> String {
         .trim()
         .trim_end_matches('.');
     let lower = detail.to_lowercase();
-    let state = if lower.contains("verifying blocks") {
+    let state = if lower.contains("loading block index") {
+        Some("loading its block index. This can take a while after installation or restart")
+    } else if lower.contains("replaying blocks") {
+        Some("checking saved blocks before startup completes")
+    } else if lower.contains("verifying blocks") {
         Some("verifying blocks after restart")
     } else if lower.contains("connection reset") {
         Some("starting up and not yet accepting RPC connections")
@@ -340,3 +344,21 @@ mod tests {
         assert!(msg.len() < 260);
     }
 }
+
+#[cfg(test)]
+mod startup_message_tests {
+    #[test]
+    fn loading_block_index_is_explained_without_rpc_error_dump() {
+        for cached in [false, true] {
+            let message = super::friendly_transient_error(
+                cached,
+                r#"getblockchaininfo: Bitcoin RPC returned 500 Internal Server Error: {"error":{"code":-28,"message":"Loading block index…"}}"#,
+            );
+            assert!(message.contains("loading its block index"));
+            for raw in ["500", "-28", "Detail:", "getblockchaininfo", "{", "RPC"] {
+                assert!(!message.contains(raw));
+            }
+            assert_eq!(message.contains("last known state"), cached);
+        }
+    }
+}

core/archipelago/src/container/companion.rs

@@ -313,7 +313,7 @@ async fn image_id(image_ref: &str) -> Option<String> {
 /// should reference (`localhost/<base>:latest` for build, registry
 /// URL for pull).
 async fn ensure_image_present(spec: &CompanionSpec) -> Result<String> {
-    let local_image = format!("localhost/{}:latest", spec.image_base);
+    let mut local_image = format!("localhost/{}:latest", spec.image_base);
     let local_image_compat = format!("localhost/{}:local", spec.image_base);
     let registry_image = format!("{}/{}:latest", COMPANION_REGISTRY, spec.image_base);
 
@@ -322,11 +322,13 @@ async fn ensure_image_present(spec: &CompanionSpec) -> Result<String> {
     for dir in spec.build_dir_candidates {
         let dockerfile = PathBuf::from(dir).join("Dockerfile");
         if fs::try_exists(&dockerfile).await.unwrap_or(false) {
-            // `:local` is a deliberate manual override — never auto-rebuild it.
+            // Older installers and self-update create :local themselves. It
+            // must receive source updates too; treating it as a permanent
+            // manual override silently kept the old LND UI after an OTA.
             if image_exists(&local_image_compat).await {
-                return Ok(local_image_compat);
+                local_image = local_image_compat.clone();
             }
-            // Reuse the auto-built `:latest` only when the build context has NOT
+            // Reuse either local tag only when the build context has NOT
             // changed since it was built. Without this staleness check an
             // already-present image is reused forever, so edits to the baked-in
             // context (Dockerfile, nginx.conf, …) never reach the node — this is
@@ -849,20 +851,43 @@ async fn needs_repair(spec: &CompanionSpec) -> Result<bool> {
     if !matches_known_shape {
         return Ok(true);
     }
-    if on_disk.contains(&local_image) && !on_disk.contains(&local_image_compat) {
+    if let Some(image) = managed_local_image(spec, &on_disk) {
         for dir in spec.build_dir_candidates {
             let dockerfile = PathBuf::from(dir).join("Dockerfile");
             if fs::try_exists(&dockerfile).await.unwrap_or(false) {
                 // Conservative on any timeout/error inside: reuse the cache.
-                return Ok(context_is_newer_than_image(dir, &local_image).await);
+                return Ok(context_is_newer_than_image(dir, &image).await);
             }
         }
     }
     Ok(false)
 }
 
+fn managed_local_image(spec: &CompanionSpec, unit: &str) -> Option<String> {
+    ["latest", "local"]
+        .iter()
+        .map(|tag| format!("localhost/{}:{tag}", spec.image_base))
+        .find(|image| build_unit(spec, image).render() == unit)
+}
+
 #[cfg(test)]
 mod tests {
+    #[test]
+    fn legacy_installer_local_tag_is_checked_for_source_updates_like_latest() {
+        for spec in ALL_COMPANIONS.iter().flat_map(|group| group.iter()) {
+            for tag in ["local", "latest"] {
+                let image = format!("localhost/{}:{tag}", spec.image_base);
+                let unit = build_unit(spec, &image).render();
+                assert_eq!(managed_local_image(spec, &unit), Some(image));
+            }
+            let registry = format!("{}/{}:latest", COMPANION_REGISTRY, spec.image_base);
+            assert_eq!(
+                managed_local_image(spec, &build_unit(spec, &registry).render()),
+                None
+            );
+        }
+    }
+
     use super::*;
 
     fn names(specs: &[&'static CompanionSpec]) -> Vec<&'static str> {

core/archipelago/src/container/filebrowser.rs

@@ -117,20 +117,24 @@ fn shell_quote(s: &str) -> String {
     s.replace('\'', "'\\''")
 }
 
-/// Save `bytes` into FileBrowser's storage as a new file in `dir`, named
-/// `name` or, if that's taken, `name (2)`, `name (3)`… Never overwrites.
-/// Returns the path written.
-///
-/// FileBrowser's folders belong to its rootless container range (host uid
-/// 100000, mode 755), so this service — host uid 1000, outside that range —
-/// can read them but not write into them, and filing a purchase into Files
-/// failed with EACCES (2026-09-29). When a direct write is refused, the file
-/// is written through `podman unshare`, where that range is ours, and given
-/// the folder's owner so FileBrowser manages it like its own uploads.
+/// Save a complete purchase without overwriting any existing directory entry.
+/// Both host and rootless-namespace paths publish with a no-clobber hard link.
 pub async fn save_new_file(dir: &Path, name: &str, bytes: &[u8]) -> Result<PathBuf> {
     save_new_file_with(dir, name, bytes, write_via_userns).await
 }
 
+fn validate_filename(name: &str) -> Result<()> {
+    anyhow::ensure!(
+        !name.is_empty()
+            && name != "."
+            && name != ".."
+            && !name.contains(['/', '\\', '\0'])
+            && name.len() <= 255,
+        "Invalid purchased filename"
+    );
+    Ok(())
+}
+
 async fn save_new_file_with<F, Fut>(
     dir: &Path,
     name: &str,
@@ -138,100 +142,170 @@ async fn save_new_file_with<F, Fut>(
     fallback: F,
 ) -> Result<PathBuf>
 where
-    F: FnOnce(PathBuf, Vec<u8>) -> Fut,
-    Fut: std::future::Future<Output = Result<()>>,
+    F: FnOnce(PathBuf, String, Vec<u8>) -> Fut,
+    Fut: std::future::Future<Output = Result<PathBuf>>,
 {
-    let target = unused_name(dir, name);
-    match write_direct(dir, &target, bytes).await {
-        Ok(()) => Ok(target),
-        Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied => {
-            fallback(target.clone(), bytes.to_vec())
+    validate_filename(name)?;
+    // Never follow a user-created destination directory symlink.
+    match fs::symlink_metadata(dir).await {
+        Ok(meta) => anyhow::ensure!(meta.is_dir(), "Files destination is not a directory"),
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => {}
+        Err(error) => return Err(error.into()),
+    }
+    save_after_direct_result(
+        write_direct(dir, name, bytes).await,
+        dir,
+        name,
+        bytes,
+        fallback,
+    )
+    .await
+}
+
+async fn save_after_direct_result<F, Fut>(
+    result: std::io::Result<PathBuf>,
+    dir: &Path,
+    name: &str,
+    bytes: &[u8],
+    fallback: F,
+) -> Result<PathBuf>
+where
+    F: FnOnce(PathBuf, String, Vec<u8>) -> Fut,
+    Fut: std::future::Future<Output = Result<PathBuf>>,
+{
+    match result {
+        Ok(path) => Ok(path),
+        Err(error) if error.kind() == std::io::ErrorKind::PermissionDenied => {
+            fallback(dir.to_owned(), name.to_owned(), bytes.to_vec())
                 .await
-                .with_context(|| format!("writing {} via podman unshare", target.display()))?;
-            Ok(target)
+                .context("Saving purchase in Files user namespace")
         }
-        Err(e) => Err(e).with_context(|| format!("writing {}", target.display())),
+        Err(error) => Err(error).context("Saving purchase in Files"),
     }
 }
 
-/// `dir/name`, or the first free `dir/stem (n).ext` from n = 2.
-fn unused_name(dir: &Path, name: &str) -> PathBuf {
-    let mut target = dir.join(name);
-    let (stem, ext) = match name.rsplit_once('.') {
-        Some((s, e)) if !s.is_empty() => (s.to_string(), format!(".{e}")),
-        _ => (name.to_string(), String::new()),
-    };
-    let mut n = 2;
-    while target.exists() {
-        target = dir.join(format!("{stem} ({n}){ext}"));
-        n += 1;
+fn numbered_name(name: &str, attempt: usize) -> String {
+    if attempt == 1 {
+        return name.to_owned();
+    }
+    match name.rsplit_once('.') {
+        Some((stem, extension)) if !stem.is_empty() => format!("{stem} ({attempt}).{extension}"),
+        _ => format!("{name} ({attempt})"),
     }
-    target
 }
 
-async fn write_direct(dir: &Path, target: &Path, bytes: &[u8]) -> std::io::Result<()> {
+struct PendingFile(PathBuf);
+impl Drop for PendingFile {
+    fn drop(&mut self) {
+        let _ = std::fs::remove_file(&self.0);
+    }
+}
+
+async fn write_direct(dir: &Path, name: &str, bytes: &[u8]) -> std::io::Result<PathBuf> {
+    use std::os::unix::fs::PermissionsExt;
     use tokio::io::AsyncWriteExt;
     fs::create_dir_all(dir).await?;
-    let mut f = fs::OpenOptions::new()
+    let temp_path = dir.join(format!(".archy-saving-{}", uuid::Uuid::new_v4()));
+    let mut file = fs::OpenOptions::new()
         .write(true)
         .create_new(true)
-        .open(target)
+        .mode(0o600)
+        .open(&temp_path)
         .await?;
-    let written = async {
-        f.write_all(bytes).await?;
-        f.flush().await
+    let temp = PendingFile(temp_path);
+    file.write_all(bytes).await?;
+    file.set_permissions(std::fs::Permissions::from_mode(0o644))
+        .await?;
+    file.sync_all().await?;
+    for attempt in 1..=100 {
+        let target = dir.join(numbered_name(name, attempt));
+        match fs::hard_link(&temp.0, &target).await {
+            Ok(()) => return Ok(target),
+            Err(error) if error.kind() == std::io::ErrorKind::AlreadyExists => continue,
+            Err(error) => return Err(error),
+        }
     }
-    .await;
-    if written.is_err() {
-        let _ = fs::remove_file(target).await;
-    }
-    written
+    Err(std::io::Error::new(
+        std::io::ErrorKind::AlreadyExists,
+        "Too many existing copies; purchase cache retained",
+    ))
 }
 
-/// Write `bytes` (piped on stdin) to `target` from inside the rootless user
-/// namespace. It goes to a temp file first and is hard-linked into place, so
-/// FileBrowser never sees a partial file and an existing file is never
-/// replaced (`ln` refuses an existing name).
-async fn write_via_userns(target: PathBuf, bytes: Vec<u8>) -> Result<()> {
-    use tokio::io::AsyncWriteExt;
-    const SCRIPT: &str = r#"set -eu
-dst=$1
-dir=$(dirname -- "$dst")
+// Positional arguments carry all user-controlled text. mktemp prevents temp-name
+// collisions; ln -T refuses files, symlinks and directories, including races.
+const WRITE_VIA_USERNS: &str = r#"set -eu
+dir=$1
+name=$2
+expected=$3
+[ ! -L "$dir" ] || exit 1
 if [ ! -d "$dir" ]; then
-    mkdir -- "$dir"
+    mkdir -p -- "$dir"
     chown --reference="$(dirname -- "$dir")" -- "$dir"
 fi
-tmp="$dir/.archy-saving.$$"
-trap 'rm -f -- "$tmp"' EXIT
+tmp=$(mktemp "$dir/.archy-saving.XXXXXXXXXX")
+trap 'rm -f -- "$tmp"' EXIT HUP INT TERM
 cat > "$tmp"
+[ "$(wc -c < "$tmp")" -eq "$expected" ] || exit 1
 chown --reference="$dir" -- "$tmp"
 chmod 0644 -- "$tmp"
-ln -- "$tmp" "$dst"
+sync -f -- "$tmp"
+stem=$name
+ext=
+case "$name" in
+    *.*) prefix=${name%.*}; if [ -n "$prefix" ]; then stem=$prefix; ext=.${name##*.}; fi ;;
+esac
+n=1
+while [ "$n" -le 100 ]; do
+    candidate=$name
+    if [ "$n" -gt 1 ]; then candidate="$stem ($n)$ext"; fi
+    dst="$dir/$candidate"
+    if ln -T -- "$tmp" "$dst" 2>/dev/null; then
+        printf '%s' "$candidate"
+        exit 0
+    fi
+    # A conflict may be a dangling symlink; never follow it or overwrite it.
+    if [ ! -e "$dst" ] && [ ! -L "$dst" ]; then exit 1; fi
+    n=$((n + 1))
+done
+exit 1
 "#;
+
+async fn write_via_userns(dir: PathBuf, name: String, bytes: Vec<u8>) -> Result<PathBuf> {
+    use tokio::io::AsyncWriteExt;
     let mut child = tokio::process::Command::new("podman")
-        .args(["unshare", "sh", "-c", SCRIPT, "sh"])
-        .arg(&target)
+        .args(["unshare", "sh", "-c", WRITE_VIA_USERNS, "sh"])
+        .arg(&dir)
+        .arg(&name)
+        .arg(bytes.len().to_string())
+        .kill_on_drop(true)
         .stdin(std::process::Stdio::piped())
-        .stdout(std::process::Stdio::null())
+        .stdout(std::process::Stdio::piped())
         .stderr(std::process::Stdio::piped())
         .spawn()
-        .context("Failed to run podman unshare")?;
-    let mut stdin = child.stdin.take().context("podman unshare stdin")?;
-    let fed = stdin.write_all(&bytes).await;
-    drop(stdin);
-    let out = child
-        .wait_with_output()
-        .await
-        .context("Failed to wait for podman unshare")?;
-    if !out.status.success() {
-        anyhow::bail!(
-            "podman unshare exited with {}: {}",
-            out.status,
-            String::from_utf8_lossy(&out.stderr).trim()
+        .context("Starting Files namespace writer")?;
+    let mut stdin = child.stdin.take().context("Files writer stdin missing")?;
+    let operation = async {
+        let fed = stdin.write_all(&bytes).await;
+        drop(stdin);
+        let output = child.wait_with_output().await?;
+        anyhow::ensure!(
+            output.status.success(),
+            "Files namespace writer failed: {}",
+            output.status
         );
-    }
-    fed.context("Failed to pipe the file to podman unshare")?;
-    Ok(())
+        fed.context("Sending purchase bytes to Files")?;
+        let chosen =
+            String::from_utf8(output.stdout).context("Files writer returned an invalid name")?;
+        validate_filename(&chosen)?;
+        anyhow::ensure!(
+            (1..=100).any(|n| numbered_name(&name, n) == chosen),
+            "Files writer returned an unexpected name"
+        );
+        Ok(dir.join(chosen))
+    };
+    tokio::time::timeout(std::time::Duration::from_secs(120), operation)
+        .await
+        .context("Files namespace writer timed out")?
 }
 
 #[cfg(test)]
@@ -268,95 +342,232 @@ mod tests {
         let second = ensure_config(&paths).await.unwrap();
         assert_eq!(second, EnsureOutcome::Unchanged);
     }
+}
 
-    #[test]
-    fn unused_name_numbers_duplicates_and_keeps_the_extension() {
-        let dir = tempfile::tempdir().unwrap();
-        let d = dir.path();
-        assert_eq!(unused_name(d, "song.mp3"), d.join("song.mp3"));
-        std::fs::write(d.join("song.mp3"), b"").unwrap();
-        assert_eq!(unused_name(d, "song.mp3"), d.join("song (2).mp3"));
-        std::fs::write(d.join("song (2).mp3"), b"").unwrap();
-        assert_eq!(unused_name(d, "song.mp3"), d.join("song (3).mp3"));
-        std::fs::write(d.join("README"), b"").unwrap();
-        assert_eq!(unused_name(d, "README"), d.join("README (2)"));
-        std::fs::write(d.join(".hidden"), b"").unwrap();
-        assert_eq!(unused_name(d, ".hidden"), d.join(".hidden (2)"));
+#[cfg(test)]
+mod purchase_write_tests {
+    use super::*;
+    use std::{
+        collections::HashSet,
+        os::unix::fs::{symlink, PermissionsExt},
+    };
+
+    fn no_temps(dir: &Path) {
+        assert!(std::fs::read_dir(dir).unwrap().all(|e| !e
+            .unwrap()
+            .file_name()
+            .to_string_lossy()
+            .starts_with(".archy-saving")));
     }
 
     #[tokio::test]
-    async fn save_new_file_writes_directly_into_a_writable_folder() {
+    async fn direct_write_uses_complete_bytes_and_preserves_originals() {
         let dir = tempfile::tempdir().unwrap();
-        let music = dir.path().join("Music");
-        let path = save_new_file_with(&music, "a.mp3", b"abc", |_, _| async {
-            anyhow::bail!("fallback must not run")
-        })
-        .await
-        .unwrap();
-        assert_eq!(path, music.join("a.mp3"));
-        assert_eq!(std::fs::read(&path).unwrap(), b"abc");
-    }
-
-    #[tokio::test]
-    async fn save_new_file_never_overwrites_an_existing_file() {
-        let dir = tempfile::tempdir().unwrap();
-        std::fs::write(dir.path().join("a.mp3"), b"original").unwrap();
-        let path = save_new_file_with(dir.path(), "a.mp3", b"new", |_, _| async {
-            anyhow::bail!("fallback must not run")
-        })
-        .await
-        .unwrap();
-        assert_eq!(path, dir.path().join("a (2).mp3"));
+        fs::write(dir.path().join("song.mp3"), b"original")
+            .await
+            .unwrap();
+        let target = save_new_file(dir.path(), "song.mp3", b"new").await.unwrap();
+        assert_eq!(target.file_name().unwrap(), "song (2).mp3");
+        assert_eq!(fs::read(target).await.unwrap(), b"new");
         assert_eq!(
-            std::fs::read(dir.path().join("a.mp3")).unwrap(),
+            fs::read(dir.path().join("song.mp3")).await.unwrap(),
             b"original"
         );
+        no_temps(dir.path());
     }
 
-    /// Regression (2026-09-29): filing a purchase into a FileBrowser folder
-    /// owned by the container's uid range failed with EACCES. A refused
-    /// write must go through the user-namespace fallback, with the same
-    /// target and bytes.
     #[tokio::test]
-    async fn a_refused_write_goes_through_the_userns_fallback() {
-        use std::os::unix::fs::PermissionsExt;
+    async fn simultaneous_saves_publish_unique_complete_files() {
         let dir = tempfile::tempdir().unwrap();
-        let music = dir.path().join("Music");
-        std::fs::create_dir(&music).unwrap();
-        std::fs::set_permissions(&music, std::fs::Permissions::from_mode(0o555)).unwrap();
-        if std::fs::File::create(music.join("probe")).is_ok() {
-            return; // running as root: mode bits don't refuse the write
+        let mut tasks = Vec::new();
+        for n in 0..24u8 {
+            let dir = dir.path().to_owned();
+            tasks.push(tokio::spawn(async move {
+                let bytes = vec![n; 32768];
+                let path = save_new_file(&dir, "same.bin", &bytes).await.unwrap();
+                assert_eq!(fs::read(&path).await.unwrap(), bytes);
+                path
+            }));
         }
+        let mut paths = HashSet::new();
+        for task in tasks {
+            assert!(paths.insert(task.await.unwrap()));
+        }
+        assert_eq!(paths.len(), 24);
+        no_temps(dir.path());
+    }
 
-        let seen = std::sync::Mutex::new(None);
-        let path = save_new_file_with(&music, "a.mp3", b"abc", |target, bytes| {
-            *seen.lock().unwrap() = Some((target, bytes));
-            async { Ok(()) }
-        })
+    #[tokio::test]
+    async fn existing_directories_and_dangling_symlinks_are_conflicts() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::create_dir(dir.path().join("name")).await.unwrap();
+        symlink("missing", dir.path().join("name (2)")).unwrap();
+        let path = save_new_file(dir.path(), "name", b"new").await.unwrap();
+        assert_eq!(path.file_name().unwrap(), "name (3)");
+        assert!(dir.path().join("name").is_dir());
+        assert!(fs::symlink_metadata(dir.path().join("name (2)"))
+            .await
+            .unwrap()
+            .is_symlink());
+        no_temps(dir.path());
+    }
+
+    #[tokio::test]
+    async fn invalid_names_and_symlink_destination_are_refused() {
+        let dir = tempfile::tempdir().unwrap();
+        for name in [
+            "",
+            ".",
+            "..",
+            "../escape",
+            "/absolute",
+            "a/b",
+            "a\\b",
+            "a\0b",
+        ] {
+            assert!(save_new_file(dir.path(), name, b"bytes").await.is_err());
+        }
+        let outside = tempfile::tempdir().unwrap();
+        symlink(outside.path(), dir.path().join("Music")).unwrap();
+        assert!(save_new_file(&dir.path().join("Music"), "song", b"bytes")
+            .await
+            .is_err());
+        assert_eq!(std::fs::read_dir(outside.path()).unwrap().count(), 0);
+    }
+
+    #[tokio::test]
+    async fn collision_limit_preserves_all_files_and_cleans_temporary_data() {
+        let dir = tempfile::tempdir().unwrap();
+        for n in 1..=100 {
+            fs::write(dir.path().join(numbered_name("a.txt", n)), b"keep")
+                .await
+                .unwrap();
+        }
+        assert!(save_new_file(dir.path(), "a.txt", b"new").await.is_err());
+        for n in 1..=100 {
+            assert_eq!(
+                fs::read(dir.path().join(numbered_name("a.txt", n)))
+                    .await
+                    .unwrap(),
+                b"keep"
+            );
+        }
+        no_temps(dir.path());
+    }
+
+    #[tokio::test]
+    async fn permission_fallback_is_exercised_without_skipping_as_root() {
+        let dir = tempfile::tempdir().unwrap();
+        let result = save_after_direct_result(
+            Err(std::io::ErrorKind::PermissionDenied.into()),
+            dir.path(),
+            "a",
+            b"abc",
+            |dir, name, bytes| async move {
+                assert_eq!(bytes, b"abc");
+                Ok(dir.join(name))
+            },
+        )
         .await
         .unwrap();
-        assert_eq!(path, music.join("a.mp3"));
-        assert_eq!(
-            seen.into_inner().unwrap(),
-            Some((music.join("a.mp3"), b"abc".to_vec()))
-        );
-        std::fs::set_permissions(&music, std::fs::Permissions::from_mode(0o755)).unwrap();
+        assert_eq!(result, dir.path().join("a"));
+        assert!(save_after_direct_result(
+            Err(std::io::ErrorKind::PermissionDenied.into()),
+            dir.path(),
+            "a",
+            b"abc",
+            |_, _, _| async { anyhow::bail!("namespace unavailable") }
+        )
+        .await
+        .unwrap_err()
+        .to_string()
+        .contains("namespace"));
+        assert!(save_after_direct_result(
+            Err(std::io::ErrorKind::StorageFull.into()),
+            dir.path(),
+            "a",
+            b"abc",
+            |_, _, _| async { panic!("disk full must not trigger permission fallback") }
+        )
+        .await
+        .is_err());
+    }
+
+    async fn run_script(
+        dir: &Path,
+        name: &str,
+        bytes: &[u8],
+        expected: usize,
+    ) -> std::process::Output {
+        use tokio::io::AsyncWriteExt;
+        let mut child = tokio::process::Command::new("sh")
+            .args(["-c", WRITE_VIA_USERNS, "sh"])
+            .arg(dir)
+            .arg(name)
+            .arg(expected.to_string())
+            .stdin(std::process::Stdio::piped())
+            .stdout(std::process::Stdio::piped())
+            .stderr(std::process::Stdio::piped())
+            .spawn()
+            .unwrap();
+        let mut input = child.stdin.take().unwrap();
+        input.write_all(bytes).await.unwrap();
+        drop(input);
+        child.wait_with_output().await.unwrap()
     }
 
     #[tokio::test]
-    async fn a_failed_fallback_is_reported() {
-        use std::os::unix::fs::PermissionsExt;
+    async fn namespace_script_preserves_names_bytes_modes_and_existing_entries() {
         let dir = tempfile::tempdir().unwrap();
-        std::fs::set_permissions(dir.path(), std::fs::Permissions::from_mode(0o555)).unwrap();
-        if std::fs::File::create(dir.path().join("probe")).is_ok() {
-            return;
+        let folder = dir.path().join("Music");
+        let name = "song ' $() ; #.mp3";
+        for n in 1..=2 {
+            let output = run_script(&folder, name, b"abc", 3).await;
+            assert!(
+                output.status.success(),
+                "{}",
+                String::from_utf8_lossy(&output.stderr)
+            );
+            let chosen = String::from_utf8(output.stdout).unwrap();
+            assert_eq!(chosen, numbered_name(name, n));
+            let path = folder.join(chosen);
+            assert_eq!(fs::read(&path).await.unwrap(), b"abc");
+            assert_eq!(
+                fs::metadata(path).await.unwrap().permissions().mode() & 0o777,
+                0o644
+            );
         }
-        let err = save_new_file_with(dir.path(), "a.mp3", b"abc", |_, _| async {
-            anyhow::bail!("no podman")
-        })
-        .await
-        .unwrap_err();
-        assert!(format!("{err:#}").contains("no podman"));
-        std::fs::set_permissions(dir.path(), std::fs::Permissions::from_mode(0o755)).unwrap();
+        no_temps(&folder);
+    }
+
+    #[tokio::test]
+    async fn namespace_script_refuses_truncated_input_and_cleans_up() {
+        let dir = tempfile::tempdir().unwrap();
+        let output = run_script(dir.path(), "never.bin", b"partial", 100).await;
+        assert!(!output.status.success());
+        assert!(!dir.path().join("never.bin").exists());
+        no_temps(dir.path());
+    }
+
+    #[tokio::test]
+    async fn namespace_script_does_not_link_inside_existing_directory() {
+        let dir = tempfile::tempdir().unwrap();
+        fs::create_dir(dir.path().join("name")).await.unwrap();
+        symlink("missing", dir.path().join("name (2)")).unwrap();
+        let output = run_script(dir.path(), "name", b"abc", 3).await;
+        assert!(output.status.success());
+        assert_eq!(output.stdout, b"name (3)");
+        assert_eq!(
+            std::fs::read_dir(dir.path().join("name")).unwrap().count(),
+            0
+        );
+        no_temps(dir.path());
+    }
+
+    #[test]
+    fn names_keep_extensions_and_dotfiles() {
+        assert_eq!(numbered_name("a.tar.gz", 2), "a.tar (2).gz");
+        assert_eq!(numbered_name(".hidden", 2), ".hidden (2)");
+        assert_eq!(numbered_name("README", 2), "README (2)");
     }
 }

core/archipelago/src/container/lnd.rs

@@ -89,18 +89,74 @@ bitcoind.estimatemode=ECONOMICAL\n"
     Ok(EnsureOutcome::Written)
 }
 
+/// Bitcoin can accept TCP while returning RPC_IN_WARMUP for many minutes.
+/// Unlocking LND then triggers its short chain-backend timeout and a restart loop.
+/// Leave the wallet intact and locked; the next reconciliation retries readiness.
+async fn bitcoin_rpc_ready() -> bool {
+    let (user, password) = crate::bitcoin_rpc::bitcoin_rpc_credentials().await;
+    let client = match reqwest::Client::builder()
+        .no_proxy()
+        .timeout(std::time::Duration::from_secs(5))
+        .build()
+    {
+        Ok(client) => client,
+        Err(_) => return false,
+    };
+    let response = client.post(crate::constants::BITCOIN_RPC_URL)
+        .basic_auth(user, Some(password))
+        .json(&serde_json::json!({"jsonrpc":"1.0","id":"lnd-readiness","method":"getblockchaininfo","params":[]}))
+        .send().await;
+    match response {
+        Ok(response) if response.status().is_success() => response
+            .json::<serde_json::Value>()
+            .await
+            .is_ok_and(|value| bitcoin_readiness_response(&value)),
+        _ => false,
+    }
+}
+
+fn bitcoin_readiness_response(value: &serde_json::Value) -> bool {
+    value.get("error").is_none_or(|e| e.is_null())
+        && value
+            .pointer("/result/blocks")
+            .and_then(|v| v.as_u64())
+            .is_some()
+        && value
+            .pointer("/result/initialblockdownload")
+            .and_then(|v| v.as_bool())
+            .is_some()
+}
+
 pub async fn ensure_wallet_initialized() -> Result<()> {
     let admin_macaroon = "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/admin.macaroon";
     let wallet_db = "/var/lib/archipelago/lnd/data/chain/bitcoin/mainnet/wallet.db";
     if file_exists_as_root(wallet_db).await {
+        // GetInfo can wait for Bitcoin sync even though the wallet is already
+        // unlocked. State RPC stays available during that normal startup phase.
+        let client = reqwest::Client::builder()
+            .no_proxy()
+            .timeout(std::time::Duration::from_secs(5))
+            .danger_accept_invalid_certs(true)
+            .build()?;
+        if wallet_is_unlocked(wallet_state(&client).await.as_deref()) {
+            return Ok(());
+        }
         if file_exists_as_root(admin_macaroon).await && lnd_getinfo_ready(admin_macaroon).await {
             return Ok(());
         }
+        if !bitcoin_rpc_ready().await {
+            tracing::debug!("[lnd] waiting for Bitcoin RPC readiness before wallet unlock");
+            return Ok(());
+        }
         unlock_existing_wallet_no_wipe().await?;
         wait_for_admin_macaroon(admin_macaroon).await?;
         return Ok(());
     }
 
+    if !bitcoin_rpc_ready().await {
+        tracing::debug!("[lnd] waiting for Bitcoin RPC readiness before wallet initialization");
+        return Ok(());
+    }
     init_wallet_via_rest().await?;
     wait_for_admin_macaroon(admin_macaroon).await
 }
@@ -258,6 +314,9 @@ async fn unlock_existing_wallet_via_rest() -> Result<bool> {
     // exactly the nodes least able to afford it. Waiting longer costs nothing —
     // a wrong password still exits on the first pass via `all_rejected`.
     for _ in 0..UNLOCK_NOT_READY_ATTEMPTS {
+        if wallet_is_unlocked(wallet_state(&client).await.as_deref()) {
+            return Ok(true);
+        }
         let mut all_rejected = true;
         for pw in &candidates {
             match try_unlock_once(&client, pw).await {
@@ -294,6 +353,10 @@ pub(crate) async fn unlock_existing_wallet_no_wipe() -> Result<()> {
     }
 }
 
+fn wallet_is_unlocked(state: Option<&str>) -> bool {
+    matches!(state, Some("UNLOCKED" | "RPC_ACTIVE" | "SERVER_ACTIVE"))
+}
+
 /// Current LND wallet state via the unauthenticated `/v1/state` endpoint
 /// (NON_EXISTING / LOCKED / UNLOCKED / RPC_ACTIVE / …). None if unreachable.
 async fn wallet_state(client: &reqwest::Client) -> Option<String> {
@@ -1089,3 +1152,44 @@ mod tests {
         .is_empty());
     }
 }
+
+#[cfg(test)]
+mod bitcoin_readiness_tests {
+    use super::bitcoin_readiness_response;
+    use serde_json::json;
+    #[test]
+    fn only_usable_bitcoin_rpc_allows_wallet_unlock() {
+        for response in [
+            json!({}),
+            json!({"error":{"code":-28,"message":"Loading block index"},"result":null}),
+            json!({"result":{"blocks":null}}),
+        ] {
+            assert!(!bitcoin_readiness_response(&response));
+        }
+        // Initial sync is supported by LND. Loading the database is not.
+        for ibd in [true, false] {
+            assert!(bitcoin_readiness_response(
+                &json!({"result":{"blocks":100,"initialblockdownload":ibd},"error":null})
+            ));
+        }
+    }
+}
+
+#[cfg(test)]
+mod syncing_wallet_state_tests {
+    #[test]
+    fn an_unlocked_wallet_waiting_for_chain_sync_is_never_unlocked_again() {
+        for state in ["UNLOCKED", "RPC_ACTIVE", "SERVER_ACTIVE"] {
+            assert!(super::wallet_is_unlocked(Some(state)));
+        }
+        for state in [
+            None,
+            Some("LOCKED"),
+            Some("NON_EXISTING"),
+            Some("WAITING_TO_START"),
+            Some("unknown"),
+        ] {
+            assert!(!super::wallet_is_unlocked(state));
+        }
+    }
+}

core/archipelago/src/container/prod_orchestrator.rs

@@ -798,6 +798,10 @@ fn host_port_bindings_drifted(
 }
 
 async fn ensure_user_podman_socket() -> Result<()> {
+    // Unit tests inject a runtime; they must not restart the host Podman API.
+    if cfg!(test) {
+        return Ok(());
+    }
     let socket_path = "/run/user/1000/podman/podman.sock";
     if podman_socket_accepts_connections(socket_path).await {
         return Ok(());
@@ -1170,15 +1174,21 @@ impl ReconcileReport {
 fn cascade_pairs_for_report<'r>(
     report: &'r ReconcileReport,
     user_stopped: &std::collections::HashSet<String>,
+    changed_backends: &HashSet<String>,
 ) -> Vec<(&'r str, &'static str)> {
     let mut pairs = Vec::new();
     for (backend, action) in &report.actions {
         if !matches!(
             action,
-            ReconcileAction::Installed | ReconcileAction::Started
+            ReconcileAction::NoOp | ReconcileAction::Started | ReconcileAction::Installed
         ) {
             continue;
         }
+        // A successful systemctl start can be a no-op after a transient
+        // Podman inspect failure. Require a witnessed lifecycle change.
+        if !changed_backends.contains(backend) {
+            continue;
+        }
         for dep in crate::app_ops::address_caching_dependents(backend) {
             let dep_untouched = report
                 .actions
@@ -1192,6 +1202,25 @@ fn cascade_pairs_for_report<'r>(
     pairs
 }
 
+/// Only positive runtime evidence permits disrupting an address-caching wallet.
+/// A known absent/stopped backend becoming running, a new container ID, or a
+/// changed start timestamp qualifies. A failed observation never does.
+fn backend_instance_changed(before: Option<&ContainerStatus>, after: &ContainerStatus) -> bool {
+    if after.state != ContainerState::Running || after.id.is_empty() {
+        return false;
+    }
+    let Some(before) = before else {
+        return true;
+    };
+    if before.id.is_empty() {
+        return false;
+    }
+    if before.id != after.id || before.state != ContainerState::Running {
+        return true;
+    }
+    matches!((&before.started_at, &after.started_at), (Some(a), Some(b)) if !a.is_empty() && !b.is_empty() && a != b)
+}
+
 #[derive(Debug, Default)]
 pub struct AdoptionReport {
     pub adopted: Vec<String>,
@@ -1905,14 +1934,40 @@ impl ProdContainerOrchestrator {
             _ => 2,
         });
         // Live container names (any state), for the same recovery check.
-        let present_containers: std::collections::HashSet<String> = self
-            .runtime
-            .list_containers()
-            .await
-            .map(|cs| cs.into_iter().map(|c| c.name).collect())
+        let listed_containers = self.runtime.list_containers().await.ok();
+        let present_containers: HashSet<String> = listed_containers
+            .as_ref()
+            .map(|cs| cs.iter().map(|c| c.name.clone()).collect())
             .unwrap_or_default();
+        // Keep unknown distinct from confirmed absence. Runtime queries can
+        // fail under load while systemd still has a healthy running backend.
+        let mut backend_before: HashMap<String, Option<ContainerStatus>> = HashMap::new();
+        for lm in &manifests {
+            let id = &lm.manifest.app.id;
+            if crate::app_ops::address_caching_dependents(id).is_empty() {
+                continue;
+            }
+            let name = compute_container_name(&lm.manifest);
+            match self.runtime.get_container_status(&name).await {
+                Ok(status) => {
+                    backend_before.insert(id.clone(), Some(status));
+                }
+                Err(_) if listed_containers.is_some() && !present_containers.contains(&name) => {
+                    backend_before.insert(id.clone(), None);
+                }
+                Err(err) => {
+                    tracing::warn!(backend = %id, error = %err,
+                        "cannot observe backend before reconcile; will not infer a dependency restart from an action report");
+                }
+            }
+        }
         let mut report = ReconcileReport::default();
         let disk_gb = self.disk_gb().await;
+        let bitcoin_pruned = disk_gb < ARCHIVAL_BITCOIN_DISK_GB
+            || crate::settings::bitcoin_storage::load(&self.data_dir)
+                .await
+                .map(|settings| settings.prune)
+                .unwrap_or(true);
         // Register every candidate before the (sequential, possibly slow)
         // pass so the scanner overlays queued-but-down apps as Restarting
         // instead of Stopped. Each app is deregistered as its turn finishes,
@@ -1952,7 +2007,7 @@ impl ProdContainerOrchestrator {
             }
             if mode == ReconcileMode::ExistingOnly
                 && requires_archival_bitcoin(&app_id)
-                && disk_gb < ARCHIVAL_BITCOIN_DISK_GB
+                && bitcoin_pruned
             {
                 report.record(
                     &app_id,
@@ -2087,7 +2142,20 @@ impl ProdContainerOrchestrator {
         // state recovery, repair recreate, boot InstallMissing) moves the
         // address behind a running dependent's back — §C "restart lnd after
         // ANY bitcoin recreate".
-        for (backend, dep) in cascade_pairs_for_report(&report, &user_stopped) {
+        let mut changed_backends = HashSet::new();
+        for (backend, before) in &backend_before {
+            let Some(name) = container_name_by_app_id.get(backend) else {
+                continue;
+            };
+            if let Ok(after) = self.runtime.get_container_status(name).await {
+                if backend_instance_changed(before.as_ref(), &after) {
+                    changed_backends.insert(backend.clone());
+                }
+            }
+        }
+        // A user stop during a slow reconcile pass still takes precedence.
+        let user_stopped = crate::crash_recovery::load_user_stopped(&self.data_dir).await;
+        for (backend, dep) in cascade_pairs_for_report(&report, &user_stopped, &changed_backends) {
             // Same rule as the RPC cascade: hold the dependent's op lock
             // across the restart; skip when a worker is mid-sequence.
             let lock = crate::app_ops::op_lock(dep);
@@ -3226,6 +3294,9 @@ impl ProdContainerOrchestrator {
     }
 
     async fn ensure_container_network(&self, manifest: &AppManifest) -> Result<()> {
+        if cfg!(test) {
+            return Ok(());
+        }
         let Some(network) = manifest.app.container.network.as_deref() else {
             return Ok(());
         };
@@ -3720,6 +3791,17 @@ impl ProdContainerOrchestrator {
         }
         let mut env = manifest.app.environment.clone();
         env.extend(manifest.app.container.resolve_derived_env(&facts));
+        if matches!(manifest.app.id.as_str(), "bitcoin-core" | "bitcoin-knots") {
+            let storage = crate::settings::bitcoin_storage::load(&self.data_dir).await?;
+            env.retain(|entry| !entry.starts_with("BITCOIN_PRUNE="));
+            if storage.prune {
+                anyhow::ensure!(
+                    manifest.app.container.custom_args.iter().any(|arg| arg.contains("BITCOIN_PRUNE")),
+                    "This Bitcoin app definition cannot honor the pruning choice. Refresh the app catalog and try again."
+                );
+                env.push("BITCOIN_PRUNE=1".to_string());
+            }
+        }
 
         // FM_BITCOIND_URL now comes from the manifest's {{BITCOIN_HOST}}
         // derived_env (works on Knots/Core/any distro). The old hardcoded
@@ -6073,6 +6155,48 @@ app:
         );
     }
 
+    #[tokio::test]
+    async fn bitcoin_storage_choice_is_applied_and_old_catalog_cannot_silently_ignore_it() {
+        let rt = Arc::new(MockRuntime::default());
+        let mut orch = orch_with(rt).await;
+        let dir = tempfile::tempdir().unwrap();
+        orch.set_data_dir(dir.path().to_path_buf());
+        for id in ["bitcoin-core", "bitcoin-knots"] {
+            let mut old = pull_manifest(id, "docker.io/bitcoin/bitcoin:28");
+            // No preference: existing containers need no new environment flag.
+            crate::settings::bitcoin_storage::save(dir.path(), false)
+                .await
+                .unwrap();
+            orch.resolve_dynamic_env(&mut old).await.unwrap();
+            assert!(!old
+                .app
+                .environment
+                .iter()
+                .any(|s| s.starts_with("BITCOIN_PRUNE=")));
+            crate::settings::bitcoin_storage::save(dir.path(), true)
+                .await
+                .unwrap();
+            assert!(orch
+                .resolve_dynamic_env(&mut old)
+                .await
+                .unwrap_err()
+                .to_string()
+                .contains("cannot honor"));
+            let mut current = pull_manifest(id, "docker.io/bitcoin/bitcoin:28");
+            current
+                .app
+                .container
+                .custom_args
+                .push("if [ ${BITCOIN_PRUNE:-0} = 1 ]; then :; fi".into());
+            orch.resolve_dynamic_env(&mut current).await.unwrap();
+            assert!(current
+                .app
+                .environment
+                .iter()
+                .any(|s| s == "BITCOIN_PRUNE=1"));
+        }
+    }
+
     #[tokio::test]
     async fn install_resolves_derived_and_secret_env_before_create() {
         let rt = Arc::new(MockRuntime::default());
@@ -6344,6 +6468,67 @@ app:
         );
     }
 
+    #[test]
+    fn backend_cascade_requires_observed_instance_change() {
+        let running = ContainerStatus {
+            id: "container-1".into(),
+            name: "bitcoin-core".into(),
+            state: ContainerState::Running,
+            started_at: Some("start-1".into()),
+            health: None,
+            exit_code: None,
+            image: "bitcoin:1".into(),
+            created: "created-1".into(),
+            ports: vec![],
+            lan_address: None,
+        };
+        assert!(!backend_instance_changed(Some(&running), &running));
+        assert!(backend_instance_changed(None, &running));
+        let mut before = running.clone();
+        before.state = ContainerState::Exited;
+        assert!(backend_instance_changed(Some(&before), &running));
+        before = running.clone();
+        before.id = "old-container".into();
+        assert!(backend_instance_changed(Some(&before), &running));
+        before = running.clone();
+        before.started_at = Some("earlier-start".into());
+        assert!(backend_instance_changed(Some(&before), &running));
+        before.started_at = None;
+        assert!(!backend_instance_changed(Some(&before), &running));
+        before.id.clear();
+        assert!(!backend_instance_changed(Some(&before), &running));
+        let mut after = running.clone();
+        after.state = ContainerState::Exited;
+        assert!(!backend_instance_changed(None, &after));
+        after = running.clone();
+        after.id.clear();
+        assert!(!backend_instance_changed(None, &after));
+    }
+
+    #[test]
+    fn cascade_ignores_false_started_report_but_detects_real_exec_drift() {
+        let none = HashSet::new();
+        let mut report = ReconcileReport {
+            actions: vec![
+                ("bitcoin-core".into(), ReconcileAction::Started),
+                ("lnd".into(), ReconcileAction::NoOp),
+            ],
+            failures: vec![],
+        };
+        // systemctl start of an already active unit does not move its address.
+        assert!(cascade_pairs_for_report(&report, &none, &none).is_empty());
+        // A unit exec rewrite can restart Bitcoin while the outer reconcile
+        // action remains NoOp. Runtime evidence still requires LND to reconnect.
+        let changed = ["bitcoin-core".into()].into();
+        report.actions[0].1 = ReconcileAction::NoOp;
+        assert_eq!(
+            cascade_pairs_for_report(&report, &none, &changed),
+            vec![("bitcoin-core", "lnd")]
+        );
+        report.actions[0].1 = ReconcileAction::Left("lifecycle-op-in-flight".into());
+        assert!(cascade_pairs_for_report(&report, &none, &changed).is_empty());
+    }
+
     #[test]
     fn cascade_pairs_cover_backend_recreate_with_running_dependent() {
         use std::collections::HashSet;
@@ -6355,6 +6540,7 @@ app:
             failures: vec![],
         };
         let none = HashSet::new();
+        let changed: HashSet<String> = ["bitcoin-core".into(), "bitcoin-knots".into()].into();
 
         // Backend recreated while lnd sat running (NoOp) → cascade.
         let r = report(vec![
@@ -6362,7 +6548,7 @@ app:
             ("lnd", ReconcileAction::NoOp),
         ]);
         assert_eq!(
-            cascade_pairs_for_report(&r, &none),
+            cascade_pairs_for_report(&r, &none, &changed),
             vec![("bitcoin-knots", "lnd")]
         );
 
@@ -6372,7 +6558,7 @@ app:
             ("lnd", ReconcileAction::NoOp),
         ]);
         assert_eq!(
-            cascade_pairs_for_report(&r, &none),
+            cascade_pairs_for_report(&r, &none, &changed),
             vec![("bitcoin-core", "lnd")]
         );
 
@@ -6381,7 +6567,7 @@ app:
             ("bitcoin-knots", ReconcileAction::NoOp),
             ("lnd", ReconcileAction::NoOp),
         ]);
-        assert!(cascade_pairs_for_report(&r, &none).is_empty());
+        assert!(cascade_pairs_for_report(&r, &none, &none).is_empty());
 
         // Dependent itself (re)started this pass → it already resolved the
         // fresh address; no cascade.
@@ -6389,7 +6575,7 @@ app:
             ("bitcoin-knots", ReconcileAction::Installed),
             ("lnd", ReconcileAction::Started),
         ]);
-        assert!(cascade_pairs_for_report(&r, &none).is_empty());
+        assert!(cascade_pairs_for_report(&r, &none, &changed).is_empty());
 
         // User-stopped dependent is never bounced.
         let r = report(vec![
@@ -6397,14 +6583,14 @@ app:
             ("lnd", ReconcileAction::NoOp),
         ]);
         let stopped: HashSet<String> = ["lnd".to_string()].into();
-        assert!(cascade_pairs_for_report(&r, &stopped).is_empty());
+        assert!(cascade_pairs_for_report(&r, &stopped, &changed).is_empty());
 
         // Non-backend recreates don't cascade anything.
         let r = report(vec![
             ("grafana", ReconcileAction::Installed),
             ("lnd", ReconcileAction::NoOp),
         ]);
-        assert!(cascade_pairs_for_report(&r, &none).is_empty());
+        assert!(cascade_pairs_for_report(&r, &none, &changed).is_empty());
     }
 
     #[tokio::test]

core/archipelago/src/container/quadlet.rs

@@ -184,6 +184,7 @@ pub struct QuadletUnit {
     pub no_new_privileges: bool,
     pub cpu_quota: Option<u32>,
     pub restart_policy: RestartPolicy,
+    pub stop_grace_secs: Option<u64>,
 }
 
 impl QuadletUnit {
@@ -216,6 +217,10 @@ impl QuadletUnit {
         let _ = writeln!(s, "[Container]");
         let _ = writeln!(s, "ContainerName={}", self.name);
         let _ = writeln!(s, "Image={}", self.image);
+        let grace = self
+            .stop_grace_secs
+            .unwrap_or_else(|| archipelago_container::runtime::stop_grace_secs_for(&self.name));
+        let _ = writeln!(s, "StopTimeout={grace}");
         // Pull=never: companions are pre-pulled or built. A missing image
         // must surface as a unit start failure, not a silent retry storm.
         let _ = writeln!(s, "Pull=never");
@@ -350,6 +355,15 @@ impl QuadletUnit {
         // the unit stuck in deactivating. Health/status remains app-level state,
         // not a systemd start gate.
         let _ = writeln!(s, "TimeoutStartSec=0");
+        let _ = writeln!(s, "TimeoutStopSec={}", grace.saturating_add(15));
+        // Stop explicitly before Quadlet's generated `podman rm -f`. The
+        // existing container may still carry Podman's old 10-second default;
+        // StopTimeout alone only protects containers created after migration.
+        let _ = writeln!(s, "ExecStop=");
+        let _ = writeln!(
+            s,
+            "ExecStop=/usr/bin/podman stop --ignore --time={grace} --cidfile=%t/%N.cid"
+        );
         // Restart policy + 10s backoff. RestartSec keeps a crash-loop
         // from saturating the journal. Companions: Always. Backends:
         // OnFailure (clean stops stay stopped).
@@ -525,6 +539,9 @@ impl QuadletUnit {
             // Always, not OnFailure: with quadlet's `--rm`, OnFailure left a
             // cleanly-exited app deleted and unrestarted. See RestartPolicy.
             restart_policy: RestartPolicy::Always,
+            stop_grace_secs: Some(super::prod_orchestrator::resolve_stop_grace_secs(
+                manifest, name,
+            )),
         }
     }
 }
@@ -676,6 +693,13 @@ pub async fn unit_exists(name: &str) -> bool {
 
 /// Resolve the per-user quadlet dir under $HOME. Created if missing.
 pub async fn unit_dir() -> Result<PathBuf> {
+    #[cfg(test)]
+    {
+        static TEST_UNITS: std::sync::OnceLock<PathBuf> = std::sync::OnceLock::new();
+        return Ok(TEST_UNITS
+            .get_or_init(|| tempfile::tempdir().unwrap().keep())
+            .clone());
+    }
     let home = std::env::var_os("HOME")
         .map(PathBuf::from)
         .ok_or_else(|| anyhow!("HOME not set; cannot locate quadlet unit dir"))?;
@@ -785,7 +809,11 @@ pub async fn stop_service(service: &str) -> Result<()> {
 /// corruption — so the orchestrator passes the per-app grace here. Never waits
 /// less than `QUADLET_STOP_TIMEOUT`.
 pub async fn stop_service_with_timeout(service: &str, timeout: Duration) -> Result<()> {
-    let timeout = timeout.max(QUADLET_STOP_TIMEOUT);
+    let name = service.strip_suffix(".service").unwrap_or(service);
+    let body = fs::read_to_string(unit_dir().await?.join(format!("{name}.container")))
+        .await
+        .unwrap_or_default();
+    let timeout = timeout.max(stop_wait_timeout(name, &body));
     match systemctl_user_status(&["stop", service], timeout).await {
         Ok(status) if status.success() => Ok(()),
         Ok(status) => Err(anyhow!("systemctl --user stop {service} exited {status}")),
@@ -806,10 +834,29 @@ pub async fn stop_service_with_timeout(service: &str, timeout: Duration) -> Resu
     }
 }
 
+/// The command waiter must outlive both the container grace and systemd's
+/// stop deadline. Restart/repair callers must not kill Bitcoin at 45 seconds.
+fn stop_wait_timeout(name: &str, unit_body: &str) -> Duration {
+    Duration::from_secs(stop_grace_from_unit(name, unit_body).saturating_add(30))
+        .max(QUADLET_STOP_TIMEOUT)
+}
+
+fn stop_grace_from_unit(name: &str, unit_body: &str) -> u64 {
+    directive_values(unit_body, "StopTimeout=")
+        .last()
+        .and_then(|value| value.parse::<u64>().ok())
+        .unwrap_or_else(|| archipelago_container::runtime::stop_grace_secs_for(name))
+}
+
 async fn systemctl_user_status(
     args: &[&str],
     timeout: Duration,
 ) -> Result<std::process::ExitStatus> {
+    #[cfg(test)]
+    {
+        use std::os::unix::process::ExitStatusExt;
+        return Ok(std::process::ExitStatus::from_raw(0));
+    }
     let mut cmd = Command::new("systemctl");
     cmd.arg("--user").args(args);
     cmd.kill_on_drop(true);
@@ -856,6 +903,10 @@ async fn wait_not_deactivating(service: &str, timeout: Duration) -> bool {
 }
 
 async fn systemctl_user_output(args: &[&str], timeout: Duration) -> Result<std::process::Output> {
+    #[cfg(test)]
+    {
+        anyhow::bail!("Unit tests have no real user service manager");
+    }
     let mut cmd = Command::new("systemctl");
     cmd.arg("--user").args(args);
     cmd.kill_on_drop(true);
@@ -923,6 +974,10 @@ fn directive_values(unit_body: &str, prefix: &str) -> Vec<String> {
 /// that systemd no longer knows about.
 pub async fn disable_remove(unit_name: &str, dir: &Path) -> Result<()> {
     let svc = format!("{unit_name}.service");
+    let path = dir.join(format!("{unit_name}.container"));
+    let body = fs::read_to_string(&path).await.unwrap_or_default();
+    let timeout = stop_wait_timeout(unit_name, &body);
+    let grace = stop_grace_from_unit(unit_name, &body).to_string();
     // Stop first; ignore failure (unit may already be down). BOUNDED — on
     // rootless podman a generated unit can wedge in "deactivating" while
     // `podman rm -f` hangs underneath it, and an unbounded `systemctl stop`
@@ -930,13 +985,12 @@ pub async fn disable_remove(unit_name: &str, dir: &Path) -> Result<()> {
     // the package entry is stranded in `Removing` (a ghost in My Apps that also
     // blocks reinstall). If the graceful stop times out, escalate to
     // SIGKILL + reset-failed so teardown always proceeds.
-    if systemctl_user_status(&["stop", &svc], QUADLET_STOP_TIMEOUT)
+    if systemctl_user_status(&["stop", &svc], timeout)
         .await
         .is_err()
     {
         let _ = kill_and_reset_service(&svc).await;
     }
-    let path = dir.join(format!("{unit_name}.container"));
     if fs::try_exists(&path).await.unwrap_or(false) {
         match fs::remove_file(&path).await {
             Ok(()) => {}
@@ -949,9 +1003,9 @@ pub async fn disable_remove(unit_name: &str, dir: &Path) -> Result<()> {
     // Bounded so a hung podman store can't re-introduce the stall this function
     // exists to avoid.
     let _ = tokio::time::timeout(
-        QUADLET_STOP_TIMEOUT,
+        timeout,
         Command::new("podman")
-            .args(["rm", "-f", unit_name])
+            .args(["rm", "-f", "--ignore", "--time", &grace, unit_name])
             .status(),
     )
     .await;
@@ -960,6 +1014,9 @@ pub async fn disable_remove(unit_name: &str, dir: &Path) -> Result<()> {
 
 /// Is the quadlet-generated service currently active?
 pub async fn is_active(service: &str) -> bool {
+    if cfg!(test) {
+        return false;
+    }
     Command::new("systemctl")
         .args(["--user", "is-active", "--quiet", service])
         .status()
@@ -973,6 +1030,118 @@ mod tests {
     use super::*;
     use tempfile::tempdir;
 
+    #[test]
+    fn shutdown_grace_covers_container_systemd_and_caller() {
+        for (name, grace) in [
+            ("bitcoin-core", 600),
+            ("bitcoin-knots", 600),
+            ("lnd", 330),
+            ("electrumx", 300),
+            ("other", 30),
+        ] {
+            let unit = QuadletUnit {
+                name: name.into(),
+                ..Default::default()
+            };
+            let body = unit.render();
+            assert!(body.contains(&format!("StopTimeout={grace}\n")));
+            assert!(body.contains(&format!("TimeoutStopSec={}\n", grace + 15)));
+            assert!(body.contains(&format!("podman stop --ignore --time={grace} --cidfile=")));
+            assert_eq!(
+                stop_wait_timeout(name, &body),
+                Duration::from_secs(grace + 30)
+            );
+            // Legacy units have no StopTimeout directive yet.
+            assert_eq!(stop_wait_timeout(name, ""), Duration::from_secs(grace + 30));
+        }
+    }
+
+    #[test]
+    fn custom_stop_grace_survives_render_and_restart_budget() {
+        let manifest: AppManifest = serde_yaml::from_str(
+            r#"
+app:
+  id: custom-db
+  name: Custom database
+  version: 1.0.0
+  stop_grace_secs: 900
+  container:
+    image: example/db:1
+"#,
+        )
+        .unwrap();
+        let unit = QuadletUnit::from_manifest(&manifest, "custom-db");
+        assert_eq!(unit.stop_grace_secs, Some(900));
+        assert_eq!(
+            stop_wait_timeout("custom-db", &unit.render()),
+            Duration::from_secs(930)
+        );
+        assert_eq!(
+            stop_wait_timeout("lnd", "StopTimeout=invalid"),
+            Duration::from_secs(360)
+        );
+    }
+
+    #[test]
+    fn stop_grace_migration_does_not_request_an_execution_restart() {
+        let unit = sample_unit();
+        let new = unit.render();
+        let old = new
+            .lines()
+            .filter(|line| {
+                !line.starts_with("StopTimeout=")
+                    && !line.starts_with("TimeoutStopSec=")
+                    && !line.starts_with("ExecStop=")
+            })
+            .collect::<Vec<_>>()
+            .join("\n");
+        assert!(!exec_changed(&old, &new));
+        assert!(!publish_ports_changed(&old, &new));
+        assert!(!network_aliases_changed(&old, &new));
+        assert!(!health_cmd_changed(&old, &new));
+    }
+
+    #[test]
+    fn actual_quadlet_generator_stops_before_forced_removal() {
+        let generator = Path::new("/usr/lib/systemd/system-generators/podman-system-generator");
+        if !generator.exists() {
+            eprintln!(
+                "Quadlet generator unavailable; run this regression on the Linux release host"
+            );
+            return;
+        }
+        let dir = tempdir().unwrap();
+        let unit = QuadletUnit {
+            name: "grace-test".into(),
+            image: "localhost/test:latest".into(),
+            stop_grace_secs: Some(600),
+            ..Default::default()
+        };
+        std::fs::write(dir.path().join("grace-test.container"), unit.render()).unwrap();
+        let output = std::process::Command::new(generator)
+            .args(["--user", "--dryrun"])
+            .env("QUADLET_UNIT_DIRS", dir.path())
+            .output()
+            .unwrap();
+        assert!(
+            output.status.success(),
+            "{}",
+            String::from_utf8_lossy(&output.stderr)
+        );
+        let generated = String::from_utf8_lossy(&output.stdout).to_string()
+            + &String::from_utf8_lossy(&output.stderr);
+        let stop = generated
+            .find("ExecStop=/usr/bin/podman stop --ignore --time=600")
+            .unwrap();
+        let remove = generated.find("ExecStop=/usr/bin/podman rm ").unwrap();
+        assert!(
+            stop < remove,
+            "Legacy container must stop gracefully before removal"
+        );
+        assert!(generated.contains("--stop-timeout 600"));
+        assert!(generated.contains("TimeoutStopSec=615"));
+    }
+
     #[test]
     fn render_emits_secret_env_by_reference_never_value() {
         let u = QuadletUnit {

core/archipelago/src/content_server.rs

@@ -296,6 +296,24 @@ pub async fn serve_content(
         }
     }
 
+    let file_path = content_file_path(data_dir, item);
+    if !file_path.exists() {
+        // The catalog entry survived (it's a separate JSON file) but its
+        // backing file is gone — most likely lost in an unrelated data-dir
+        // reset (a shared filebrowser file, 2026-07-01: two catalog entries
+        // outlived a filebrowser reinstall that wiped the files themselves).
+        // Leaving the entry in place would keep advertising it as available
+        // to every peer forever, each hitting the exact same dead end this
+        // one just did. Prune it so it stops being offered.
+        warn!(
+            content_id = %id,
+            filename = %item.filename,
+            "content catalog entry's file is missing on disk — pruning the stale entry"
+        );
+        prune_missing_content_entry(data_dir, id).await;
+        return Ok(ServeResult::NotFound);
+    }
+
     // Check access control
     if !owner_session {
         match &item.access {
@@ -307,8 +325,12 @@ pub async fn serve_content(
                 // Each path only counts when the sharer accepts that method.
                 let mut authorized = false;
                 if let Some(token) = payment_token {
-                    if (method_accepted(&item.access, "ecash")
-                        || method_accepted(&item.access, "fedimint"))
+                    let method = if token.trim().starts_with("cashu") {
+                        "ecash"
+                    } else {
+                        "fedimint"
+                    };
+                    if method_accepted(&item.access, method)
                         && verify_payment_token(data_dir, token, *price_sats).await
                     {
                         authorized = true;
@@ -336,24 +358,6 @@ pub async fn serve_content(
         }
     }
 
-    let file_path = content_file_path(data_dir, item);
-    if !file_path.exists() {
-        // The catalog entry survived (it's a separate JSON file) but its
-        // backing file is gone — most likely lost in an unrelated data-dir
-        // reset (a shared filebrowser file, 2026-07-01: two catalog entries
-        // outlived a filebrowser reinstall that wiped the files themselves).
-        // Leaving the entry in place would keep advertising it as available
-        // to every peer forever, each hitting the exact same dead end this
-        // one just did. Prune it so it stops being offered.
-        warn!(
-            content_id = %id,
-            filename = %item.filename,
-            "content catalog entry's file is missing on disk — pruning the stale entry"
-        );
-        prune_missing_content_entry(data_dir, id).await;
-        return Ok(ServeResult::NotFound);
-    }
-
     let metadata = fs::metadata(&file_path)
         .await
         .context("Failed to read file metadata")?;
@@ -573,7 +577,7 @@ pub async fn serve_content_preview(data_dir: &Path, id: &str) -> Result<PreviewR
 }
 
 /// Verify a payment token covers the required amount.
-/// Accepts both cashuA tokens (real Cashu) and legacy cashuSend_ format.
+/// Accepts real Cashu tokens and Fedimint notes.
 /// Swaps proofs at the mint to verify they're unspent before accepting.
 async fn verify_payment_token(data_dir: &Path, token: &str, required_sats: u64) -> bool {
     match crate::wallet::ecash::verify_and_receive_payment(data_dir, token, required_sats).await {

core/archipelago/src/settings/bitcoin_storage.rs

@@ -0,0 +1,51 @@
+//! Install-time pruning preference, shared by Bitcoin Core and Knots.
+//! Missing preference preserves the existing disk-based automatic selection.
+use anyhow::{Context, Result};
+use serde::{Deserialize, Serialize};
+use std::path::Path;
+
+#[derive(Default, Serialize, Deserialize)]
+pub struct BitcoinStorage {
+    pub prune: bool,
+}
+
+pub async fn load(data_dir: &Path) -> Result<BitcoinStorage> {
+    match tokio::fs::read(data_dir.join("settings/bitcoin-storage.json")).await {
+        Ok(bytes) => serde_json::from_slice(&bytes).context("Invalid Bitcoin storage settings"),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(BitcoinStorage::default()),
+        Err(e) => Err(e.into()),
+    }
+}
+
+pub async fn save(data_dir: &Path, prune: bool) -> Result<()> {
+    let dir = data_dir.join("settings");
+    tokio::fs::create_dir_all(&dir).await?;
+    let path = dir.join("bitcoin-storage.json");
+    let temporary = dir.join("bitcoin-storage.json.tmp");
+    tokio::fs::write(&temporary, serde_json::to_vec(&BitcoinStorage { prune })?).await?;
+    tokio::fs::rename(temporary, path).await?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[tokio::test]
+    async fn missing_setting_keeps_auto_and_explicit_pruning_survives_reload() {
+        let dir = tempfile::tempdir().unwrap();
+        assert!(!load(dir.path()).await.unwrap().prune);
+        save(dir.path(), true).await.unwrap();
+        assert!(load(dir.path()).await.unwrap().prune);
+        save(dir.path(), false).await.unwrap();
+        assert!(!load(dir.path()).await.unwrap().prune);
+    }
+    #[tokio::test]
+    async fn corrupt_setting_is_not_silently_changed_to_archival() {
+        let dir = tempfile::tempdir().unwrap();
+        save(dir.path(), true).await.unwrap();
+        tokio::fs::write(dir.path().join("settings/bitcoin-storage.json"), "broken")
+            .await
+            .unwrap();
+        assert!(load(dir.path()).await.is_err());
+    }
+}

core/archipelago/src/settings/mod.rs

@@ -7,3 +7,5 @@
 pub mod ai_permissions;
 pub mod session_policy;
 pub mod transport;
+
+pub mod bitcoin_storage;

core/archipelago/src/update.rs

@@ -1481,6 +1481,21 @@ pub async fn cancel_download(data_dir: &Path) -> Result<()> {
 /// service unit that inherits systemd's default protections (i.e. none
 /// of ours), escaping the namespace.
 pub(crate) async fn host_sudo(args: &[&str]) -> Result<std::process::ExitStatus> {
+    #[cfg(test)]
+    {
+        anyhow::ensure!(
+            std::env::var("ARCHY_TEST_ISOLATED").as_deref() == Ok("1"),
+            "Host-operation tests require scripts/test-backend-isolated.sh"
+        );
+        let (program, args) = args.split_first().context("Missing test command")?;
+        // Run inside the test namespace, never escape through sudo/systemd-run.
+        return tokio::process::Command::new(program)
+            .args(args)
+            .status()
+            .await
+            .context("isolated test command failed");
+    }
+
     let mut full: Vec<&str> = vec![
         "systemd-run",
         "--wait",
@@ -1505,6 +1520,21 @@ pub(crate) async fn host_sudo(args: &[&str]) -> Result<std::process::ExitStatus>
 /// Same mechanism as `host_sudo` but captures stdout — for read-only probes
 /// (e.g. `stat`) where the answer is in the output, not the exit status.
 pub(crate) async fn host_sudo_output(args: &[&str]) -> Result<std::process::Output> {
+    #[cfg(test)]
+    {
+        anyhow::ensure!(
+            std::env::var("ARCHY_TEST_ISOLATED").as_deref() == Ok("1"),
+            "Host-operation tests require scripts/test-backend-isolated.sh"
+        );
+        let (program, args) = args.split_first().context("Missing test command")?;
+        // Run inside the test namespace, never escape through sudo/systemd-run.
+        return tokio::process::Command::new(program)
+            .args(args)
+            .output()
+            .await
+            .context("isolated test command failed");
+    }
+
     let mut full: Vec<&str> = vec![
         "systemd-run",
         "--wait",

core/archipelago/src/wallet/ecash.rs

@@ -775,7 +775,9 @@ pub async fn send_token_at(data_dir: &Path, mint_url: &str, amount_sats: u64) ->
         let mut all_target: Vec<u64> = send_denoms.clone();
         all_target.extend(&change_denoms);
 
-        let swap_result = client.swap(&selected_proofs, &all_target).await?;
+        let swap_result = client
+            .swap_at_least(&selected_proofs, &all_target, amount_sats)
+            .await?;
 
         // Mark original proofs as spent
         wallet.mark_spent(&indices);
@@ -1192,7 +1194,11 @@ pub async fn receive_token(data_dir: &Path, token_str: &str) -> Result<u64> {
     // Verify all mints in the token are accepted
     let accepted = load_accepted_mints(data_dir).await?;
     for mint_url in token.mint_urls() {
-        if !accepted.mints.iter().any(|m| m == mint_url) {
+        if !accepted
+            .mints
+            .iter()
+            .any(|m| m.trim_end_matches('/') == mint_url.trim_end_matches('/'))
+        {
             anyhow::bail!("Mint '{}' is not in accepted mints list", mint_url);
         }
     }
@@ -1217,7 +1223,7 @@ pub async fn receive_token(data_dir: &Path, token_str: &str) -> Result<u64> {
                 received_total += amount;
             }
             Err(e) => {
-                warn!("Failed to swap proofs from mint {}: {:#}", entry.mint, e);
+                warn!("Failed to swap proofs from mint {}: {}", entry.mint, e);
                 all_already_redeemed &= e.is::<super::mint_client::AlreadyRedeemed>();
                 last_reason = Some(e.to_string());
                 // Continue with other mints if any
@@ -1298,22 +1304,10 @@ pub async fn verify_and_receive_payment(
     token_str: &str,
     required_sats: u64,
 ) -> Result<u64> {
-    // Handle legacy tokens
+    let token_str = token_str.trim();
+    // Synthetic legacy balances are not cryptographic proof of payment.
     if token_str.starts_with("cashuSend_") {
-        let amount = token_str
-            .split('_')
-            .nth(1)
-            .and_then(|s| s.parse::<u64>().ok())
-            .unwrap_or(0);
-        if amount < required_sats {
-            anyhow::bail!(
-                "Insufficient payment: {} sats, need {} sats",
-                amount,
-                required_sats
-            );
-        }
-        let received = receive_legacy_token(data_dir, token_str).await?;
-        return Ok(received);
+        anyhow::bail!("Legacy ecash cannot authorize a paid download");
     }
 
     // Fedimint notes (#3): a buyer whose balance is in Fedimint pays with notes
@@ -1336,52 +1330,45 @@ pub async fn verify_and_receive_payment(
 
     // Parse and validate the token (cashuA or cashuB)
     let token = CashuToken::deserialize(token_str)?;
-    let total = token.total_amount();
-
+    if token.unit.as_deref().unwrap_or("sat") != "sat" {
+        anyhow::bail!("Payment must be denominated in sats");
+    }
+    // A sale must redeem atomically at one mint. Otherwise a later mint
+    // failure can consume earlier inputs without delivering the purchase.
+    let entry = match token.token.as_slice() {
+        [entry] => entry,
+        _ => anyhow::bail!("Use a single-mint token for this payment"),
+    };
+    let total = entry
+        .proofs
+        .iter()
+        .try_fold(0u64, |sum, p| sum.checked_add(p.amount))
+        .ok_or_else(|| anyhow::anyhow!("Payment amount overflow"))?;
     if total < required_sats {
-        anyhow::bail!(
-            "Insufficient payment: {} sats, need {} sats",
-            total,
-            required_sats
-        );
+        anyhow::bail!("Insufficient payment: {total} sats, need {required_sats} sats");
     }
-
-    // Verify mints are accepted
     let accepted = load_accepted_mints(data_dir).await?;
-    for mint_url in token.mint_urls() {
-        if !accepted.mints.iter().any(|m| m == mint_url) {
-            anyhow::bail!("Mint '{}' not accepted", mint_url);
-        }
+    if !accepted
+        .mints
+        .iter()
+        .any(|m| m.trim_end_matches('/') == entry.mint.trim_end_matches('/'))
+    {
+        anyhow::bail!("Mint is not in the seller's accepted mints list");
     }
 
-    // Swap proofs at mint (this verifies they're unspent and gives us fresh proofs)
+    let client = mint_client(data_dir, &entry.mint).await?;
+    let result = client
+        .swap_at_least(
+            &entry.proofs,
+            &amount_to_denominations(total),
+            required_sats,
+        )
+        .await?;
+    let received_total = result.new_proofs.iter().map(|p| p.amount).sum();
+    // Load after the network call, so an unrelated wallet update during the
+    // swap is not overwritten with a pre-swap snapshot.
     let mut wallet = load_wallet(data_dir).await?;
-    let mut received_total = 0u64;
-
-    for entry in &token.token {
-        let client = mint_client(data_dir, &entry.mint).await?;
-        let entry_total: u64 = entry.proofs.iter().map(|p| p.amount).sum();
-        let target_amounts = amount_to_denominations(entry_total);
-
-        match client.swap(&entry.proofs, &target_amounts).await {
-            Ok(result) => {
-                let amount: u64 = result.new_proofs.iter().map(|p| p.amount).sum();
-                wallet.add_proofs(&entry.mint, result.new_proofs);
-                received_total += amount;
-            }
-            Err(e) => {
-                warn!("Payment verification failed at mint {}: {}", entry.mint, e);
-            }
-        }
-    }
-
-    if received_total < required_sats {
-        anyhow::bail!(
-            "Payment verification failed: only {} of {} sats verified",
-            received_total,
-            required_sats
-        );
-    }
+    wallet.add_proofs(entry.mint.trim_end_matches('/'), result.new_proofs);
 
     wallet.record_tx(
         TransactionType::Receive,
@@ -2465,3 +2452,7 @@ mod tests {
         assert_eq!(w.mint_url, "https://mint.minibits.cash/Bitcoin");
     }
 }
+
+#[cfg(test)]
+#[path = "payment_tests.rs"]
+mod payment_tests;

core/archipelago/src/wallet/mint_client.rs

@@ -153,6 +153,20 @@ fn mint_error(op: &str, status: reqwest::StatusCode, body: &str) -> anyhow::Erro
     cause.context(describe_mint_error_body(status, body))
 }
 
+fn fee_adjusted_targets(requested: &[u64], mut available: u64) -> Vec<u64> {
+    let mut outputs = Vec::new();
+    for &amount in requested {
+        if available >= amount {
+            outputs.push(amount);
+            available -= amount;
+        } else {
+            outputs.extend(amount_to_denominations(available));
+            break;
+        }
+    }
+    outputs
+}
+
 /// HTTP client for a single Cashu mint.
 pub struct MintClient {
     url: String,
@@ -512,6 +526,21 @@ impl MintClient {
     /// Swap proofs for new proofs of different denominations.
     /// This is how we "receive" a token — swap it for fresh proofs that only we know.
     pub async fn swap(&self, inputs: &[Proof], target_amounts: &[u64]) -> Result<SwapResult> {
+        self.swap_at_least(inputs, target_amounts, 0).await
+    }
+
+    /// Refuse a payment whose mint fees would leave the seller underpaid,
+    /// before consuming any input proofs.
+    pub async fn swap_at_least(
+        &self,
+        inputs: &[Proof],
+        target_amounts: &[u64],
+        minimum: u64,
+    ) -> Result<SwapResult> {
+        // V4 tokens carry short keyset IDs. Every swap path (including paid
+        // files and streams) must expand these, not only wallet imports.
+        let resolved = self.resolve_truncated_keyset_ids(inputs).await?;
+        let inputs = resolved.as_slice();
         let keyset = self.get_active_sat_keyset().await?;
 
         // NUT-02: a mint may charge a per-input fee, and it rejects the swap
@@ -519,16 +548,35 @@ impl MintClient {
         // should equal outputs less fee`). Applied here rather than at each
         // call site so send, receive and cross-mint swaps are all covered.
         // Fee-free mints (Minibits) compute 0 and are unaffected.
-        let inputs_total: u64 = inputs.iter().map(|p| p.amount).sum();
-        let fee = match self.get_keysets().await {
-            Ok(ks) => super::cashu::swap_fee_for(inputs, &ks),
-            Err(e) => {
-                debug!("Could not read keyset fees ({e:#}) — assuming fee-free mint");
-                0
-            }
-        };
+        anyhow::ensure!(!inputs.is_empty(), "No input proofs to swap");
+        let inputs_total = inputs
+            .iter()
+            .try_fold(0u64, |sum, p| sum.checked_add(p.amount))
+            .context("Input amount overflow")?;
+        let keysets = self.get_keysets().await?;
+        let mut fee_ppk = 0u64;
+        for proof in inputs {
+            let input_keyset = keysets
+                .iter()
+                .find(|k| k.id == proof.id)
+                .context("The mint does not recognize an input keyset")?;
+            anyhow::ensure!(
+                input_keyset.unit == "sat",
+                "Input keyset is not denominated in sats"
+            );
+            fee_ppk = fee_ppk
+                .checked_add(input_keyset.input_fee_ppk)
+                .context("Mint fee overflow")?;
+        }
+        let fee = fee_ppk.div_ceil(1000);
         let spendable = inputs_total.saturating_sub(fee);
-        let requested: u64 = target_amounts.iter().sum();
+        if spendable < minimum {
+            anyhow::bail!("Payment would leave {spendable} sats after mint fees; need {minimum} sats. No proofs were redeemed.");
+        }
+        let requested = target_amounts
+            .iter()
+            .try_fold(0u64, |sum, amount| sum.checked_add(*amount))
+            .context("Output amount overflow")?;
         let owned_targets: Vec<u64>;
         let target_amounts: &[u64] = if requested > spendable {
             if spendable == 0 {
@@ -539,7 +587,10 @@ impl MintClient {
             debug!(
                 "Reducing swap outputs {requested} -> {spendable} to cover a {fee} sat mint fee"
             );
-            owned_targets = amount_to_denominations(spendable);
+            // Callers put payment outputs before change. Keep that prefix
+            // intact while fees reduce change; re-splitting the entire sum
+            // can omit a payment denomination after consuming the inputs.
+            owned_targets = fee_adjusted_targets(target_amounts, spendable);
             &owned_targets
         } else {
             target_amounts
@@ -584,6 +635,9 @@ impl MintClient {
 
         let mut new_proofs = Vec::new();
         for (sig, (secret, r, amount)) in signatures.iter().zip(blinding_data.iter()) {
+            if sig.amount != *amount || sig.id != keyset.id {
+                anyhow::bail!("Mint returned a swap signature for an unexpected amount or keyset");
+            }
             let c_prime = sig.c_prime_as_pubkey()?;
             let mint_key = keyset.key_for_amount(*amount)?;
             let c = bdhke::unblind_signature(&c_prime, r, &mint_key)?;
@@ -730,43 +784,35 @@ impl MintClient {
     /// Repair proofs whose keyset id is a truncated NUT-02 **v2** id.
     ///
     /// A v2 keyset id is 33 bytes (version byte `0x01` + 32-byte hash), but
-    /// wallets written against the original 8-byte format truncate it when
-    /// they build a token. The mint then reads the `0x01` version, expects 33
+    /// compact V4 tokens carry an 8-byte short ID. The swap endpoint needs
+    /// the full ID restored from the mint's keyset list. The mint then reads the `0x01` version, expects 33
     /// bytes, and rejects the swap — reported as
     /// `inputs[0].id: NUT02: ID length invalid` behind a bare 422 (seen with
     /// a Minibits-issued token, 2026-08-17).
     ///
     /// The id only names which keyset signed the proof, so restoring the full
     /// id the mint advertises is exactly what the sender meant. It is also
-    /// safe to attempt: an id that names the wrong keyset fails signature
-    /// verification at the mint and no coins move. Anything already valid, or
-    /// with no unambiguous match, is passed through untouched so the mint's
-    /// own error is what the operator sees.
-    async fn resolve_truncated_keyset_ids(&self, proofs: &[Proof]) -> Vec<Proof> {
+    /// safe to attempt: the mint still verifies the proof signature. Unknown
+    /// or ambiguous short IDs are rejected before redemption.
+    async fn resolve_truncated_keyset_ids(&self, proofs: &[Proof]) -> Result<Vec<Proof>> {
         let needs_repair = proofs.iter().any(|p| is_truncated_v2_keyset_id(&p.id));
         if !needs_repair {
-            return proofs.to_vec();
+            return Ok(proofs.to_vec());
         }
 
         // The mint's own keyset list, in the reference implementation's shape
         // so its NUT-02 resolver can consume it directly.
-        let known = match self.get_cdk_keysets().await {
-            Ok(k) => k,
-            Err(e) => {
-                debug!("Could not list keysets to repair truncated keyset ids: {e:#}");
-                return proofs.to_vec();
-            }
-        };
+        let known = self.get_cdk_keysets().await?;
 
         proofs
             .iter()
             .cloned()
             .map(|mut p| {
-                if let Some(full) = super::cashu::resolve_keyset_id(&p.id, &known) {
-                    debug!("Expanded short keyset id {} to {} for swap", p.id, full);
-                    p.id = full;
+                if is_truncated_v2_keyset_id(&p.id) {
+                    p.id = super::cashu::resolve_keyset_id(&p.id, &known)
+                        .context("The mint cannot resolve this short keyset ID unambiguously")?;
                 }
-                p
+                Ok(p)
             })
             .collect()
     }
@@ -802,7 +848,7 @@ impl MintClient {
         let mut all_new_proofs = Vec::new();
 
         for entry in &token.token {
-            if entry.mint != self.url {
+            if entry.mint.trim_end_matches('/') != self.url {
                 debug!(
                     "Skipping proofs from different mint {} (ours: {})",
                     entry.mint, self.url
@@ -813,8 +859,7 @@ impl MintClient {
             let total: u64 = entry.proofs.iter().map(|p| p.amount).sum();
             let target_amounts = amount_to_denominations(total);
 
-            let proofs = self.resolve_truncated_keyset_ids(&entry.proofs).await;
-            let result = self.swap(&proofs, &target_amounts).await?;
+            let result = self.swap(&entry.proofs, &target_amounts).await?;
             all_new_proofs.extend(result.new_proofs);
         }
 

core/archipelago/src/wallet/payment_tests.rs

@@ -0,0 +1,428 @@
+//! Real HTTP/curve-signature regressions for paid Cashu redemption.
+use super::*;
+use crate::wallet::{bdhke, cashu::Proof};
+use bitcoin::secp256k1::{PublicKey, Scalar, Secp256k1, SecretKey};
+use hyper::{
+    service::{make_service_fn, service_fn},
+    Body, Request, Response, Server,
+};
+use serde_json::{json, Value};
+use std::{
+    convert::Infallible,
+    sync::{Arc, Mutex},
+};
+
+const ACTIVE: &str = "0011223344556677";
+const V2: &str = "011111111111111111111111111111111111111111111111111111111111111111";
+
+struct Mint {
+    url: String,
+    requests: Arc<Mutex<Vec<Value>>>,
+    task: tokio::task::JoinHandle<()>,
+    failure: Arc<std::sync::atomic::AtomicU16>,
+}
+impl Drop for Mint {
+    fn drop(&mut self) {
+        self.task.abort();
+    }
+}
+
+fn signing_key() -> SecretKey {
+    SecretKey::from_slice(&[7; 32]).unwrap()
+}
+fn signed_point(point: PublicKey) -> String {
+    point
+        .mul_tweak(&Secp256k1::new(), &Scalar::from(signing_key()))
+        .unwrap()
+        .to_string()
+}
+fn proof(id: &str, amount: u64) -> Proof {
+    let secret = format!("test-{id}-{amount}");
+    Proof {
+        amount,
+        id: id.into(),
+        c: signed_point(bdhke::hash_to_curve(secret.as_bytes()).unwrap()),
+        secret,
+    }
+}
+impl Mint {
+    async fn start(fee: u64, failure: Option<u16>) -> Self {
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        listener.set_nonblocking(true).unwrap();
+        let url = format!("http://{}", listener.local_addr().unwrap());
+        let requests = Arc::new(Mutex::new(Vec::new()));
+        let seen = requests.clone();
+        let failure = Arc::new(std::sync::atomic::AtomicU16::new(failure.unwrap_or(0)));
+        let rejection = failure.clone();
+        let spent = Arc::new(Mutex::new(std::collections::HashSet::<String>::new()));
+        let service = make_service_fn(move |_| {
+            let seen = seen.clone();
+            let rejection = rejection.clone();
+            let spent = spent.clone();
+            async move {
+                Ok::<_, Infallible>(service_fn(move |req: Request<Body>| {
+                    let seen = seen.clone();
+                    let rejection = rejection.clone();
+                    let spent = spent.clone();
+                    async move {
+                        let mut status = 200;
+                        let body = match req.uri().path() {
+                            "/v1/keysets" => json!({"keysets":[
+                                {"id": ACTIVE,"unit":"sat","active":true,"input_fee_ppk":fee},
+                                {"id": V2,"unit":"sat","active":false,"input_fee_ppk":fee}
+                            ]}),
+                            "/v1/keys" => {
+                                let public =
+                                    PublicKey::from_secret_key(&Secp256k1::new(), &signing_key())
+                                        .to_string();
+                                let keys: serde_json::Map<String, Value> = (0..16)
+                                    .map(|i| ((1u64 << i).to_string(), json!(public)))
+                                    .collect();
+                                json!({"keysets":[{"id": ACTIVE,"unit":"sat","keys":keys}]})
+                            }
+                            "/v1/swap" => {
+                                let body: Value = serde_json::from_slice(
+                                    &hyper::body::to_bytes(req.into_body()).await.unwrap(),
+                                )
+                                .unwrap();
+                                seen.lock().unwrap().push(body.clone());
+                                let inputs = body["inputs"].as_array().unwrap();
+                                let outputs = body["outputs"].as_array().unwrap();
+                                let code = rejection.load(std::sync::atomic::Ordering::SeqCst);
+                                if code != 0 {
+                                    status = code;
+                                    json!({"detail":"mock mint rejection"})
+                                } else if inputs.iter().any(|p| p["id"] != V2 && p["id"] != ACTIVE)
+                                {
+                                    status = 422;
+                                    json!({"detail":[{"msg":"NUT02: ID length invalid"}]})
+                                } else if inputs.iter().any(|p| {
+                                    spent
+                                        .lock()
+                                        .unwrap()
+                                        .contains(p["secret"].as_str().unwrap())
+                                }) {
+                                    status = 400;
+                                    json!({"code":11001,"detail":"Token Already Spent"})
+                                } else {
+                                    let total: u64 =
+                                        inputs.iter().map(|p| p["amount"].as_u64().unwrap()).sum();
+                                    let out: u64 =
+                                        outputs.iter().map(|p| p["amount"].as_u64().unwrap()).sum();
+                                    assert_eq!(
+                                        out,
+                                        total - (inputs.len() as u64 * fee).div_ceil(1000)
+                                    );
+                                    for p in inputs {
+                                        spent
+                                            .lock()
+                                            .unwrap()
+                                            .insert(p["secret"].as_str().unwrap().into());
+                                    }
+                                    json!({"signatures":outputs.iter().map(|o| json!({
+                                    "amount":o["amount"],"id":ACTIVE,
+                                    "C_":signed_point(o["B_"].as_str().unwrap().parse().unwrap())
+                                })).collect::<Vec<_>>()})
+                                }
+                            }
+                            _ => {
+                                status = 404;
+                                json!({})
+                            }
+                        };
+                        Ok::<_, Infallible>(
+                            Response::builder()
+                                .status(status)
+                                .header("Content-Type", "application/json")
+                                .body(Body::from(body.to_string()))
+                                .unwrap(),
+                        )
+                    }
+                }))
+            }
+        });
+        let server = Server::from_tcp(listener).unwrap().serve(service);
+        let task = tokio::spawn(async move {
+            server.await.unwrap();
+        });
+        Self {
+            url,
+            requests,
+            task,
+            failure,
+        }
+    }
+    async fn wallet(&self) -> tempfile::TempDir {
+        let dir = tempfile::tempdir().unwrap();
+        save_accepted_mints(
+            dir.path(),
+            &AcceptedMints {
+                mints: vec![format!("{}/", self.url)],
+            },
+        )
+        .await
+        .unwrap();
+        dir
+    }
+}
+
+#[tokio::test]
+async fn paid_v4_inactive_v2_keyset_is_expanded_and_cryptographic_proofs_saved() {
+    let mint = Mint::start(0, None).await;
+    let dir = mint.wallet().await;
+    let token = CashuToken::new(&mint.url, vec![proof(V2, 64), proof(V2, 32), proof(V2, 4)])
+        .serialize_v4()
+        .unwrap();
+    let decoded = CashuToken::deserialize(&token).unwrap();
+    assert_eq!(
+        decoded.token[0].proofs[0].id.len(),
+        16,
+        "reproduce the short V4 ID"
+    );
+    assert_eq!(
+        verify_and_receive_payment(dir.path(), &token, 100)
+            .await
+            .unwrap(),
+        100
+    );
+    let wallet = load_wallet(dir.path()).await.unwrap();
+    assert_eq!(wallet.balance(), 100);
+    for p in wallet.proofs {
+        assert_eq!(
+            p.proof.c,
+            signed_point(bdhke::hash_to_curve(p.proof.secret.as_bytes()).unwrap())
+        );
+    }
+    assert!(mint.requests.lock().unwrap()[0]["inputs"]
+        .as_array()
+        .unwrap()
+        .iter()
+        .all(|p| p["id"] == V2));
+    assert!(verify_and_receive_payment(dir.path(), &token, 100)
+        .await
+        .is_err());
+    assert_eq!(load_wallet(dir.path()).await.unwrap().balance(), 100);
+}
+
+#[tokio::test]
+async fn paid_v3_full_v2_and_v1_ids_work() {
+    for id in [V2, ACTIVE] {
+        let mint = Mint::start(0, None).await;
+        let dir = mint.wallet().await;
+        let token = CashuToken::new(&mint.url, vec![proof(id, 128)])
+            .serialize()
+            .unwrap();
+        assert_eq!(
+            verify_and_receive_payment(dir.path(), &token, 100)
+                .await
+                .unwrap(),
+            128
+        );
+    }
+}
+
+#[tokio::test]
+async fn fees_cannot_consume_underpayment_and_allowed_fees_credit_actual_value() {
+    let mint = Mint::start(1000, None).await;
+    let dir = mint.wallet().await;
+    let token = CashuToken::new(&mint.url, vec![proof(V2, 128)])
+        .serialize_v4()
+        .unwrap();
+    assert!(verify_and_receive_payment(dir.path(), &token, 128)
+        .await
+        .unwrap_err()
+        .to_string()
+        .contains("after mint fees"));
+    assert!(mint.requests.lock().unwrap().is_empty());
+    assert_eq!(
+        verify_and_receive_payment(dir.path(), &token, 127)
+            .await
+            .unwrap(),
+        127
+    );
+    assert_eq!(load_wallet(dir.path()).await.unwrap().balance(), 127);
+}
+
+#[tokio::test]
+async fn rejected_mint_response_does_not_credit_wallet() {
+    for status in [200, 400, 422, 500, 503] {
+        let mint = Mint::start(0, Some(status)).await;
+        let dir = mint.wallet().await;
+        let token = CashuToken::new(&mint.url, vec![proof(V2, 128)])
+            .serialize_v4()
+            .unwrap();
+        assert!(verify_and_receive_payment(dir.path(), &token, 100)
+            .await
+            .is_err());
+        assert_eq!(load_wallet(dir.path()).await.unwrap().balance(), 0);
+    }
+}
+
+#[tokio::test]
+async fn invalid_untrusted_multimint_and_underpaid_tokens_never_reach_swap() {
+    let mint = Mint::start(0, None).await;
+    let dir = mint.wallet().await;
+    let token = CashuToken::new(&mint.url, vec![proof(V2, 128)]);
+    let mut invalid = vec![
+        "cashuSend_500_abc_1700000000".into(),
+        "cashuBinvalid".into(),
+    ];
+    let mut wrong_unit = token.clone();
+    wrong_unit.unit = Some("usd".into());
+    invalid.push(wrong_unit.serialize().unwrap());
+    let mut multi = token.clone();
+    multi.token.push(token.token[0].clone());
+    invalid.push(multi.serialize().unwrap());
+    let mut untrusted = token.clone();
+    untrusted.token[0].mint = "http://127.0.0.1:1".into();
+    invalid.push(untrusted.serialize().unwrap());
+    for id in ["00ffffffffffffff", "01ffffffffffffff"] {
+        invalid.push(
+            CashuToken::new(&mint.url, vec![proof(id, 128)])
+                .serialize()
+                .unwrap(),
+        );
+    }
+    for value in invalid {
+        assert!(verify_and_receive_payment(dir.path(), &value, 100)
+            .await
+            .is_err());
+    }
+    assert!(
+        verify_and_receive_payment(dir.path(), &token.serialize().unwrap(), 129)
+            .await
+            .is_err()
+    );
+    assert!(mint.requests.lock().unwrap().is_empty());
+    assert_eq!(load_wallet(dir.path()).await.unwrap().balance(), 0);
+}
+
+#[tokio::test]
+async fn buyer_token_rejected_by_seller_can_be_refunded_without_balance_loss() {
+    let mint = Mint::start(0, Some(422)).await;
+    let buyer = mint.wallet().await;
+    let seller = mint.wallet().await;
+    let mut wallet = load_wallet(buyer.path()).await.unwrap();
+    wallet.mint_url = mint.url.clone();
+    wallet.add_proofs(&mint.url, vec![proof(V2, 64), proof(V2, 32), proof(V2, 4)]);
+    save_wallet(buyer.path(), &wallet).await.unwrap();
+    let token = send_token(buyer.path(), 100).await.unwrap();
+    assert_eq!(load_wallet(buyer.path()).await.unwrap().balance(), 0);
+    assert!(verify_and_receive_payment(seller.path(), &token, 100)
+        .await
+        .is_err());
+    mint.failure.store(0, std::sync::atomic::Ordering::SeqCst);
+    assert_eq!(receive_token(buyer.path(), &token).await.unwrap(), 100);
+    assert_eq!(load_wallet(buyer.path()).await.unwrap().balance(), 100);
+    assert_eq!(load_wallet(seller.path()).await.unwrap().balance(), 0);
+    assert!(receive_token(buyer.path(), &token).await.is_err());
+    assert_eq!(load_wallet(buyer.path()).await.unwrap().balance(), 100);
+}
+
+#[tokio::test]
+async fn unreachable_mint_does_not_credit_seller() {
+    let mint = Mint::start(0, None).await;
+    let dir = mint.wallet().await;
+    let token = CashuToken::new(&mint.url, vec![proof(V2, 128)])
+        .serialize_v4()
+        .unwrap();
+    mint.task.abort();
+    tokio::task::yield_now().await;
+    assert!(verify_and_receive_payment(dir.path(), &token, 100)
+        .await
+        .is_err());
+    assert_eq!(load_wallet(dir.path()).await.unwrap().balance(), 0);
+}
+
+#[tokio::test]
+async fn send_with_fees_preserves_payment_denominations_and_saves_change() {
+    // 128 inputs - 2 fee = 126. Splitting 126 as one sum omits 1,
+    // which is needed for a 65-sat payment, after consuming the inputs.
+    let mint = Mint::start(1000, None).await;
+    let buyer = mint.wallet().await;
+    let mut wallet = load_wallet(buyer.path()).await.unwrap();
+    wallet.mint_url = mint.url.clone();
+    let first = proof(V2, 64);
+    let mut second = first.clone();
+    second.secret.push_str("-second");
+    second.c = signed_point(bdhke::hash_to_curve(second.secret.as_bytes()).unwrap());
+    wallet.add_proofs(&mint.url, vec![first, second]);
+    save_wallet(buyer.path(), &wallet).await.unwrap();
+    let encoded = send_token(buyer.path(), 65).await.unwrap();
+    assert_eq!(
+        CashuToken::deserialize(&encoded).unwrap().total_amount(),
+        65
+    );
+    assert_eq!(load_wallet(buyer.path()).await.unwrap().balance(), 61);
+}
+
+#[tokio::test]
+async fn paid_file_gate_delivers_bytes_only_after_payment_and_does_not_charge_missing_files() {
+    use crate::content_server::{
+        self, AccessControl, Availability, ContentCatalog, ContentItem, ServeResult,
+    };
+    for (exists, accepts_cashu, price) in [
+        (true, true, 100),
+        (true, false, 100),
+        (false, true, 100),
+        (true, true, 129),
+    ] {
+        let mint = Mint::start(0, None).await;
+        let seller = mint.wallet().await;
+        let item = ContentItem {
+            id: "paid-test".into(),
+            filename: "test.txt".into(),
+            mime_type: "text/plain".into(),
+            size_bytes: 5,
+            description: String::new(),
+            added_at: String::new(),
+            availability: Availability::AllPeers,
+            access: AccessControl::Paid {
+                price_sats: price,
+                accepted: vec![if accepts_cashu { "ecash" } else { "fedimint" }.into()],
+            },
+        };
+        content_server::save_catalog(seller.path(), &ContentCatalog { items: vec![item] })
+            .await
+            .unwrap();
+        if exists {
+            tokio::fs::create_dir_all(seller.path().join("content/files"))
+                .await
+                .unwrap();
+            tokio::fs::write(seller.path().join("content/files/test.txt"), b"hello")
+                .await
+                .unwrap();
+        }
+        let token = CashuToken::new(&mint.url, vec![proof(V2, 128)])
+            .serialize_v4()
+            .unwrap();
+        let result = content_server::serve_content(
+            seller.path(),
+            "paid-test",
+            Some(&token),
+            None,
+            None,
+            None,
+            false,
+        )
+        .await
+        .unwrap();
+        if exists && accepts_cashu && price <= 128 {
+            match result {
+                ServeResult::Ok(bytes, mime) => {
+                    assert_eq!(bytes, b"hello");
+                    assert_eq!(mime, "text/plain");
+                }
+                _ => panic!("paid content was not delivered"),
+            }
+            assert_eq!(load_wallet(seller.path()).await.unwrap().balance(), 128);
+        } else {
+            assert!(matches!(
+                result,
+                ServeResult::NotFound | ServeResult::PaymentRequired(_)
+            ));
+            assert_eq!(load_wallet(seller.path()).await.unwrap().balance(), 0);
+            assert!(mint.requests.lock().unwrap().is_empty());
+        }
+    }
+}