Store usage database in ComfyUI user directory

Moves the SQLite database from the extension folder to
ComfyUI/user/nodes_stats/ so stats survive reinstalls.
Automatically migrates existing data on first load.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tracker.py

@@ -7,7 +7,23 @@ from datetime import datetime, timezone, timedelta
 
 logger = logging.getLogger(__name__)
 
-DB_PATH = os.path.join(os.path.dirname(__file__), "usage_stats.db")
+
+def _default_db_path():
+    """Store the DB in ComfyUI's user directory so it survives extension reinstalls."""
+    try:
+        import folder_paths
+
+        user_dir = folder_paths.get_user_directory()
+        db_dir = os.path.join(user_dir, "nodes_stats")
+        os.makedirs(db_dir, exist_ok=True)
+        return os.path.join(db_dir, "usage_stats.db")
+    except Exception:
+        # Fallback to extension directory if folder_paths is unavailable
+        return os.path.join(os.path.dirname(__file__), "usage_stats.db")
+
+
+DB_PATH = _default_db_path()
+_OLD_DB_PATH = os.path.join(os.path.dirname(__file__), "usage_stats.db")
 
 SCHEMA = """
 CREATE TABLE IF NOT EXISTS node_usage (
@@ -47,6 +63,7 @@ class UsageTracker:
         """Create tables on first use. Called under self._lock."""
         if self._initialized:
             return
+        self._migrate_old_db()
         conn = sqlite3.connect(self._db_path)
         try:
             conn.executescript(SCHEMA)
@@ -55,6 +72,22 @@ class UsageTracker:
             conn.close()
         self._initialized = True
 
+    def _migrate_old_db(self):
+        """Move DB from old extension-local path to the new user directory."""
+        if self._db_path == _OLD_DB_PATH:
+            return
+        if not os.path.exists(_OLD_DB_PATH):
+            return
+        if os.path.exists(self._db_path):
+            # New location already has data, skip migration
+            return
+        try:
+            import shutil
+            shutil.move(_OLD_DB_PATH, self._db_path)
+            logger.info("nodes-stats: migrated DB to %s", self._db_path)
+        except Exception:
+            logger.warning("nodes-stats: failed to migrate old DB", exc_info=True)
+
     def _connect(self):
         return sqlite3.connect(self._db_path)