Add more meta information to trove entries

trovedb/db.py

@@ -71,7 +71,7 @@ class Sqlite3Trove:
             con.commit()
         obj = cls(con)
         if initialize:
-            obj.write_blob(b"", NODE_ROOT_ID)
+            obj.write_blob(b"", NOTE_ROOT_ID)
         return obj
 
     def close(self):
@@ -103,6 +103,15 @@ class Sqlite3Trove:
             return None
         return bytes(row["data"]) if row["data"] is not None else b""
 
+    def get_mtime(self, object_id: int) -> datetime | None:
+        """Return the modified timestamp for an object, or None if not found."""
+        row = self._con.execute(
+            "SELECT modified FROM objects WHERE id = ?", (object_id,)
+        ).fetchone()
+        if row is None:
+            return None
+        return datetime.fromisoformat(row["modified"])
+
     def read_metadata(self, object_id: int, key: str) -> bytes | None:
         """Return raw metadata value for (uuid, key), or None if not found."""
         row = self._con.execute(