bascially ready to ship

main.py

@@ -1,8 +1,16 @@
 #!/usr/bin/env python3
 """Session Mover TUI - Move OpenCode sessions between projects without SQL."""
 
+import sys
+from pathlib import Path
 from app import SessionMoverApp
 
 if __name__ == "__main__":
-    app = SessionMoverApp()
+    db_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("opencode.db")
+
+    if not db_path.exists():
+        print(f"Error: database file not found: {db_path}", file=sys.stderr)
+        sys.exit(1)
+
+    app = SessionMoverApp(str(db_path))
     app.run()