fix(tools): resolve config path inside container

tools/import_fans_csv.py

@@ -224,7 +224,13 @@ def _database_path(config_path: str, override: str | None) -> Path:
         return Path(override)
     from reaction_board.config import ConfigStore
 
-    return ConfigStore(config_path, require_auth=False).get().storage.database_path
+    candidates = [Path(config_path), Path("/config/config.json")]
+    for candidate in candidates:
+        if candidate.exists():
+            return ConfigStore(str(candidate), require_auth=False).get().storage.database_path
+    raise ValueError(
+        "找不到配置文件；请用 --db /data/app.db 或 --config /config/config.json"
+    )
 
 
 def main(argv: Sequence[str] | None = None) -> int: