fix: correct PostgreSQL migration parameter passing

Why this change is needed:
PostgreSQLDB.execute() expects data as a dictionary, not multiple
positional arguments. The migration code was incorrectly unpacking
a list with *values, causing TypeError.

How it solves it:
- Changed values from list to dict: {col: row_dict[col] for col in columns}
- Pass values dict directly to execute() without unpacking
- Matches execute() signature which expects dict[str, Any] | None

Impact:
- Fixes PostgreSQL E2E test failures
- Enables successful legacy data migration for PostgreSQL

Testing:
- Will be verified by PostgreSQL E2E tests in CI

lightrag/kg/postgres_impl.py

@@ -2350,9 +2350,9 @@ class PGVectorStorage(BaseVectorStorage):
                         ON CONFLICT DO NOTHING
                     """
 
-                    # AsyncPG requires positional parameters as a list in order
-                    values = [row_dict[col] for col in columns]
-                    await db.execute(insert_query, *values)
+                    # Construct dict for execute() method
+                    values = {col: row_dict[col] for col in columns}
+                    await db.execute(insert_query, values)
 
                 migrated_count += len(rows)
                 logger.info(