fix: repair command, split args, Claude export, room keywords

- Add `mempalace repair` command to rebuild vector index from SQLite
  when HNSW files are corrupted after crash/interrupt (fixes #74, #72, #96)
- Fix split command passing dir as positional instead of --source
  flag to split_mega_files (fixes #63)
- Handle Claude privacy export format (array of conversation objects
  with chat_messages inside each) in normalize.py (fixes #63)
- Persist room keywords in mempalace.yaml so mine can match files
  in docs/ to room "documentation" (fixes #108)

mempalace/room_detector_local.py

@@ -255,7 +255,14 @@ def get_user_approval(rooms: list) -> list:
 def save_config(project_dir: str, project_name: str, rooms: list):
     config = {
         "wing": project_name,
-        "rooms": [{"name": r["name"], "description": r["description"]} for r in rooms],
+        "rooms": [
+            {
+                "name": r["name"],
+                "description": r["description"],
+                "keywords": r.get("keywords", [r["name"]]),
+            }
+            for r in rooms
+        ],
     }
     config_path = Path(project_dir).expanduser().resolve() / "mempalace.yaml"
     with open(config_path, "w") as f: