fix(orchestrator): map container uids into the subuid range in the chown fallback

chown_for_rootless_container prefers `podman unshare chown` (which maps
container uid N through the userns), but when that failed once it fell
back to `sudo chown -R <literal>` — writing e.g. host uid 999 for
container uid 999 and reporting success. Host-999 maps to nobody inside
the userns, so the app could not open its own data while everything
claimed the chown worked: botfights on framework-pt crash-looped every
10s on SQLITE_CANTOPEN over a data dir the daemon itself had just
"fixed".

The sudo fallback now translates container ids (1..99999) to
subuid_base + id - 1 (fleet base 100000; container root maps to the
service user, 1000). Already-mapped ids and uid 0 pass through.

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

core/archipelago/src/container/prod_orchestrator.rs

@@ -272,10 +272,15 @@ fn build_fingerprint_stamp_path(data_dir: &Path, tag: &str) -> PathBuf {
 }
 
 async fn chown_for_rootless_container(uid_gid: &str, path: &str) -> Result<()> {
-    let uid = uid_gid
+    let (uid, gid) = uid_gid
         .split_once(':')
-        .and_then(|(uid, _)| uid.parse::<u32>().ok())
-        .unwrap_or(0);
+        .map(|(u, g)| {
+            (
+                u.parse::<u32>().unwrap_or(0),
+                g.parse::<u32>().unwrap_or(0),
+            )
+        })
+        .unwrap_or((0, 0));
 
     if uid > 0 && uid < 100_000 {
         let output = tokio::process::Command::new("podman")
@@ -288,9 +293,22 @@ async fn chown_for_rootless_container(uid_gid: &str, path: &str) -> Result<()> {
         }
     }
 
-    let status = host_sudo(&["chown", "-R", uid_gid, path])
+    // Host-side fallback. A CONTAINER-namespace id must be translated into
+    // the subuid range first: `sudo chown 999` writes literal host uid 999,
+    // which maps to nobody inside the userns — the app then can't open its
+    // own files while the chown reported success (botfights SQLITE_CANTOPEN
+    // crash-loop, framework-pt 2026-08-06). Container uid N (N>=1) lives at
+    // subuid_base + N - 1; the fleet provisions base 100000. uid 0 and
+    // already-mapped ids (>=100000) pass through untouched.
+    let host_uid_gid = if uid > 0 && uid < 100_000 {
+        let map = |id: u32| if id == 0 { 1000 } else { 100_000 + id - 1 };
+        format!("{}:{}", map(uid), map(gid))
+    } else {
+        uid_gid.to_string()
+    };
+    let status = host_sudo(&["chown", "-R", &host_uid_gid, path])
         .await
-        .with_context(|| format!("sudo chown -R {uid_gid} {path}"))?;
+        .with_context(|| format!("sudo chown -R {host_uid_gid} {path}"))?;
     if status.success() {
         return Ok(());
     }