fix(immich): restore canonical app_id "immich" (title + icon)

After the manifest migration the launcher installed as "immich-server" (app_id),
which has no catalog entry → showed the raw id and no icon. Rename the server
manifest app_id immich-server→immich so it matches the catalog/curated "immich"
entry (title "Immich", icon immich.png) and is recognised as a known launcher app
(APP_CATEGORY_MAP) → stays in My Apps. immich_stack_app_ids now installs
[immich-postgres, immich-redis, immich]; orchestrator.install bypasses package
routing so there's no recursion with the "immich"→stack-installer mapping.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/immich/manifest.yml

@@ -1,10 +1,11 @@
 app:
-  id: immich-server
+  id: immich
   name: Immich
   version: "2.7.4"
   description: Self-hosted photo and video backup with mobile apps and search.
 
-  # Named by app_id (immich-server); connects to its siblings by their app_id
+  # app_id "immich" = the user-facing launcher (matches the catalog entry's title
+  # + icon). Container is named "immich"; it reaches its backends by their app_id
   # aliases on archy-net (see DB_HOSTNAME / REDIS_HOSTNAME below).
 
   container: