Add BACKUP_FOLDER and BACKUP_KEEP config

app/config.py

@@ -28,6 +28,15 @@ class Config:
     BRICKSET_PASSWORD = os.environ.get('BRICKSET_PASSWORD')
     BRICKSET_API_URL = 'https://brickset.com/api/v3.asmx'
     
+    # Backups
+    # Defaults to <project root>/backups so archives never land inside the
+    # uploads tree (which would make each backup include the previous one).
+    BACKUP_FOLDER = os.environ.get('BACKUP_FOLDER') or \
+        os.path.join(os.path.dirname(basedir), 'backups')
+    # Keep only the newest N archives after a backup made from the web UI.
+    # Set to 0 to keep everything.
+    BACKUP_KEEP = int(os.environ.get('BACKUP_KEEP', 5))
+
     # Pagination
     SETS_PER_PAGE = int(os.environ.get('SETS_PER_PAGE', 20))