Add explicit database import UI and harden SQL restore.

db/backup.py

@@ -2,12 +2,13 @@
 
 from __future__ import annotations
 
+import gzip
 import logging
 import os
 import subprocess
 from datetime import datetime, timezone
 
-from .connection import get_pg_connection_params
+from .connection import close_pool, get_pg_connection_params
 from .store import invalidate_data_cache
 
 logger = logging.getLogger(__name__)
@@ -25,6 +26,18 @@ def backup_filename() -> str:
     return f'amnezia_panel_backup_{stamp}.sql'
 
 
+def _decode_backup_bytes(data: bytes) -> bytes:
+    """Accept plain .sql or gzip-compressed dumps (.sql.gz / gzip magic)."""
+    if not data:
+        return data
+    if data[:2] == b'\x1f\x8b':
+        try:
+            return gzip.decompress(data)
+        except OSError as e:
+            raise ValueError(f'Invalid gzip backup: {e}') from e
+    return data
+
+
 def export_database_sql() -> bytes:
     """Create a plain SQL dump of the panel PostgreSQL database."""
     params = get_pg_connection_params()
@@ -54,8 +67,16 @@ def export_database_sql() -> bytes:
 
 def restore_database_sql(data: bytes) -> None:
     """Restore panel data from a plain SQL dump produced by pg_dump."""
+    data = _decode_backup_bytes(data)
     if not data or not data.strip():
         raise ValueError('Empty backup file')
+
+    # Drop live pool connections so --clean DROP TABLE is not blocked.
+    try:
+        close_pool()
+    except Exception as e:
+        logger.warning('close_pool before restore failed: %s', e)
+
     params = get_pg_connection_params()
     proc = subprocess.run(
         [
@@ -72,9 +93,9 @@ def restore_database_sql(data: bytes) -> None:
         check=False,
         env=_pg_cli_env(params['password']),
     )
+    invalidate_data_cache()
     if proc.returncode != 0:
         err = proc.stderr.decode('utf-8', errors='replace').strip()
         out = proc.stdout.decode('utf-8', errors='replace').strip()
         raise RuntimeError(err or out or 'psql restore failed')
-    invalidate_data_cache()
     logger.info('PostgreSQL backup restored successfully')