chore: purge retired git.tx1138.com registry host from the codebase

The tx1138 Gitea was retired as a release server 2026-06-13 and its registry
frontend is fully dead (500 on every /v2 manifest read, observed 2026-07-10).
Nothing may reference it anymore:

- registry.rs: no longer a default registry, no longer force-enabled on
  load; saved configs are stripped of it on load (same one-time migration
  treatment as the decommissioned Hetzner mirror), with a regression test.
- image_policy.rs: removed from TRUSTED_REGISTRIES — refs through the dead
  host are now refused at the pull site (rejection test added).
- api/handler: dropped the legacy catalog-proxy fallback URL.
- .gitmodules: indeedhub submodule repointed to the OVH Gitea.
- scripts, image-recipe, app-catalog data, neode-ui strings, docs, and all
  test fixtures repointed to 146.59.87.168:3000 (or neutral example hosts).
- image-versions.sh: ARCHY_REGISTRY_FALLBACK emptied (guarded consumers
  skip it); reconcile-containers.sh candidate guard hardened.

The only remaining occurrences of the host string are the strip/reject
enforcement paths and their regression tests — the code that guarantees it
is never used again.

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

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

@@ -126,15 +126,15 @@ impl ApiHandler {
     }
 
     /// Server-side fetch of the upstream app catalog so the browser can
-    /// load it without fighting CORS (git.tx1138.com emits no ACAO) or
+    /// load it without fighting CORS (upstream Gitea emits no ACAO) or
     /// CSP (the fallback IP-port URL isn't in `connect-src`). The upstream
     /// list is derived from the operator's configured container registries
     /// so switching mirrors in Settings changes the App Store source too —
     /// each active registry contributes one Gitea `raw/branch/main/catalog.json`
     /// URL (http or https per `tls_verify`), tried in priority order.
-    /// If registry config can't be loaded, falls back to the legacy
-    /// hardcoded pair so the App Store still renders on nodes that haven't
-    /// persisted a registry config yet. 15s total timeout.
+    /// If registry config can't be loaded, falls back to the hardcoded OVH
+    /// URL so the App Store still renders on nodes that haven't persisted
+    /// a registry config yet. 15s total timeout.
     async fn handle_app_catalog_proxy(&self) -> Result<Response<hyper::Body>> {
         let mut upstreams: Vec<String> = Vec::new();
         if let Ok(config) = crate::container::registry::load_registries(&self.config.data_dir).await
@@ -155,10 +155,6 @@ impl ApiHandler {
                 "http://146.59.87.168:3000/lfg2025/app-catalog/raw/branch/main/catalog.json"
                     .to_string(),
             );
-            upstreams.push(
-                "https://git.tx1138.com/lfg2025/app-catalog/raw/branch/main/catalog.json"
-                    .to_string(),
-            );
         }
 
         let client = match reqwest::Client::builder()
@@ -527,7 +523,7 @@ impl ApiHandler {
 
             // App-catalog proxy — fetches catalog.json from the configured
             // upstream URLs server-side so the browser doesn't hit CORS
-            // (git.tx1138.com has no ACAO header) or CSP (IP-port upstream
+            // (upstream Gitea has no ACAO header) or CSP (IP-port upstream
             // falls outside `connect-src`). Session-authenticated so only
             // the logged-in node owner can spin up fetches.
             (Method::GET, "/api/app-catalog") => {