fix: surface hash-duplicate warning and add manual refresh

Three issues fixed:

1. **Skipped-commit warning not visible** — When the user commits
   unchanged content (hash matches most recent version), the backend
   correctly returns {skipped: true, reason: "unchanged", message: ...}
   but the frontend Notification.warning was easy to miss (default
   4-5s autoClose, small toast at top-right). Now uses {autoClose: false}
   so the warning stays until manually dismissed, plus a console.log
   of the raw commit response for debugging. Added a fallback branch
   that warns clearly if the response shape is unexpected.

2. **No manual refresh on the panel** — In S3 setups the list call
   can occasionally lag the just-committed entry (manifest strong
   consistency is a per-implementation property). Added a "刷新"
   button at the top of the sidebar that calls model.refresh(), letting
   the user force a re-fetch when the auto-refresh misses.

3. **S3 addressing_style** — user-side config addition: S3Storage
   now uses path-style addressing (endpoint/bucket/key) which is the
   format required by MinIO and several other S3-compatible services.

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

snapshot/storage/s3.py

@@ -82,7 +82,10 @@ class S3Storage(StorageAdapter):
             aws_access_key_id=access_key,
             aws_secret_access_key=secret_key,
             region_name="us-east-1",
-            config=BotoConfig(signature_version="s3v4"),
+            config=BotoConfig(
+                signature_version='s3v4',
+                s3={'addressing_style': 'path'},
+            ),
         )
         self._ClientError = ClientError
         self._connect_and_ensure_bucket()