fix(fips): P0 uptime fixes — open peer port 5679, allow /blob+/dwn, fix LAN anchor port, un-deaden direct peering, fast-fail budgets

Phase A1 of docs/FIPS-UPTIME-AND-UI-STATE-PLAN.md — the five changes that
made FIPS fall back to Tor even when a FIPS path existed:

- RC0: the fips.d drop-in now opens PEER_PORT 5679 (was 80+8443 only, so
  every hardened node firewalled peers' FIPS dials; 28k drops on .198)
- RC4: /blob/ and /dwn/ added to the peer-path allowlist — mesh file
  sharing and DWN sync were 404 → 100% Tor by construction
- RC2-G2: lan_fips_anchors dials PUBLISHED_UDP_PORT (2121) instead of the
  dead 8668, with a drift-guard test against the rendered daemon config
- RC2-G1: direct LAN peering actually runs now — mDNS TXT advertises the
  FIPS npub, discovery calls set_fips_npub, and the anchor tick hydrates
  npubs from federation storage for peers on older builds
- RC3: FIPS attempt budget is a hard cap (retry no longer doubles it) and
  the 12 hot call sites get explicit fips_timeout fast-fail so Tor keeps
  its full budget (browse-peer, preview, /blob, DWN, node-message,
  rotation notifies)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/server.rs

@@ -433,8 +433,18 @@ impl Server {
                         ),
                     ));
 
-                    // LAN transport (mDNS discovery)
-                    let mut lan = crate::transport::lan::LanTransport::new(&did, &pubkey_hex, 5678);
+                    // LAN transport (mDNS discovery). Advertise our FIPS npub in
+                    // the TXT record so co-located peers can form a direct FIPS
+                    // link (see `lan_fips_anchors`).
+                    let local_fips_npub = crate::identity::fips_npub(&data_dir.join("identity"))
+                        .await
+                        .unwrap_or(None);
+                    let mut lan = crate::transport::lan::LanTransport::new(
+                        &did,
+                        &pubkey_hex,
+                        5678,
+                        local_fips_npub,
+                    );
                     match lan.start(registry.clone()) {
                         Ok(()) => info!("📡 LAN transport (mDNS) started"),
                         Err(e) => debug!("LAN transport init (non-fatal): {}", e),
@@ -753,12 +763,25 @@ impl Server {
                     // (often flaky) global anchor's spanning tree to route to each
                     // other. For every peer the registry knows both a LAN address
                     // AND a FIPS npub for, dial it on its FIPS UDP transport port
-                    // (8668) at its LAN IP. This is FIPS's own transport over the
+                    // at its LAN IP. This is FIPS's own transport over the
                     // LAN — NOT Tailscale, NOT the HTTP/LAN messaging port. Pure
                     // FIPS. `fipsctl connect` is idempotent, so re-applying every
                     // tick just keeps the direct link warm; unknown/remote peers
                     // (no LAN address) are left to the anchor as before.
                     if let Some(reg) = fips_peer_registry.as_ref() {
+                        // Hydrate FIPS npubs into the registry from federation
+                        // storage (did-keyed). Peers discovered before the mDNS
+                        // TXT `fips` key existed — or running builds that don't
+                        // advertise it yet — would otherwise never satisfy the
+                        // `fips_npub` requirement in lan_fips_anchors(), leaving
+                        // direct LAN peering a no-op.
+                        if let Ok(nodes) = crate::federation::load_nodes(&data_dir).await {
+                            for n in &nodes {
+                                if let Some(npub) = n.fips_npub.as_deref() {
+                                    reg.set_fips_npub(&n.did, npub).await;
+                                }
+                            }
+                        }
                         let direct = crate::fips::anchors::lan_fips_anchors(&reg.all_peers().await);
                         if !direct.is_empty() {
                             let _ = crate::fips::anchors::apply(&direct).await;
@@ -1241,6 +1264,12 @@ pub fn is_peer_allowed_path(path: &str) -> bool {
     )
     // Prefix-matched content endpoints (peer file browse + fetch)
         || path.starts_with("/content/")
+        // Mesh file sharing — blob fetch by CID, signature-gated in the
+        // handler. Absent from this list it 404'd over FIPS and the feature
+        // was 100% Tor by construction.
+        || path.starts_with("/blob/")
+        // DWN sync — /dwn/health is step 1 of every sync; same story.
+        || path.starts_with("/dwn/")
 }
 
 async fn accept_loop(
@@ -1944,10 +1973,17 @@ mod merge_tests {
         );
         assert!(is_peer_allowed_path("/rpc/v1"));
         assert!(is_peer_allowed_path("/health"));
+        // Mesh blob fetch + DWN sync — both were missing from the allowlist,
+        // which made them deterministically 404 over FIPS and therefore
+        // 100% Tor by construction.
+        assert!(is_peer_allowed_path("/blob/abc123"), "blob fetch by CID");
+        assert!(is_peer_allowed_path("/dwn/health"), "DWN sync step 1");
         // Not on the allow-list → rejected (no broad surface over the mesh).
         assert!(!is_peer_allowed_path("/contention"), "must not prefix-leak");
         assert!(!is_peer_allowed_path("/"));
         assert!(!is_peer_allowed_path("/rpc/v2"));
+        assert!(!is_peer_allowed_path("/blobber"), "must not prefix-leak");
+        assert!(!is_peer_allowed_path("/dwnx"), "must not prefix-leak");
     }
 
     #[test]