chore: Add detailed logging for migration state update

Added logging to trace the final migration state update process:
- Log final count from PostgreSQL
- Log final last ID from table
- Log before and after _update_migration_state() call

This helps debug why migration_state might not be getting updated
when migration completes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/migrator/full_migration.py

@@ -161,6 +161,7 @@ class FullMigrator:
 
                     # Get final actual count from PostgreSQL
                     final_count = pg_conn.get_row_count(pg_table)
+                    logger.info(f"Final count from PostgreSQL: {final_count}")
 
                     # Update migration state with final count and mark as completed
                     # Get the actual last ID from the table
@@ -171,12 +172,16 @@ class FullMigrator:
                             )
                             result = cursor.fetchone()
                             final_last_id = result[0] if result and result[0] else None
-                    except Exception:
+                        logger.info(f"Final last ID from table: {final_last_id}")
+                    except Exception as e:
+                        logger.warning(f"Failed to get final last ID: {e}")
                         final_last_id = None
 
+                    logger.info(f"About to update migration_state with count={final_count}, last_id={final_last_id}")
                     self._update_migration_state(
                         pg_conn, final_count, final_last_id, migration_start_time
                     )
+                    logger.info(f"Migration state update complete")
 
                     logger.info(
                         f"✓ Migration complete: {final_count} total rows in {pg_table}"