feat(trip-cluster): idempotent write-back + CLI apply with confirmation

apps/trip-cluster/app/cli.py

@@ -41,6 +41,30 @@ def cmd_cluster(deps, *, gap_factor) -> int:
     return 0
 
 
+def cmd_apply(deps, *, yes) -> int:
+    cfg = deps["config"]
+    store = _store(cfg)
+    from app.writeback import apply_all, APPLYABLE
+    pending = [c for c in store.all_clusters() if c.status in APPLYABLE]
+    if not pending:
+        print("Nothing to apply.")
+        store.close()
+        return 0
+    if not yes:
+        ans = input(f"Apply {len(pending)} cluster decision(s) to Immich? [y/N] ")
+        if ans.strip().lower() not in ("y", "yes"):
+            print("Aborted.")
+            store.close()
+            return 1
+    client = _immich(deps, cfg)
+    results = apply_all(client, store)
+    store.close()
+    ok = sum(len(r["succeeded"]) for r in results)
+    bad = sum(len(r["failed"]) for r in results)
+    print(f"Applied {ok} tag write(s); {bad} failure(s) across {len(results)} cluster(s).")
+    return 0 if bad == 0 else 1
+
+
 def cmd_serve(deps) -> int:
     from app import create_app
     create_app(deps["config"]).run(host="0.0.0.0", port=8084)
@@ -79,7 +103,8 @@ def main(argv=None) -> int:
                           tag=args.tag, subset=args.subset, full=args.full)
     if args.command == "cluster":
         return cmd_cluster(deps, gap_factor=args.gap_factor)
-    # apply is wired in a later task.
+    if args.command == "apply":
+        return cmd_apply(deps, yes=args.yes)
     print(f"Command '{args.command}' is not implemented yet.")
     return 1