feat(settings): filename templates for download and bulk rename (#1071)

Add per-model-type filename templates ({model_name}, {version_name},
{base_model}, {author}, {first_tag}, {hash_short}, {original_name}) so
downloaded files get informative names instead of e.g. V1.safetensors.
Empty template keeps the current filename (opt-in, off by default).

- apply template automatically after downloads; rename conflicts keep
  the original name and never fail the download
- record original_file_name in metadata on rename for traceability
- bulk apply via GET|POST /api/lm/{prefix}/apply-filename-template with
  WebSocket progress, sharing the auto-organize lock
- settings UI lives in the new Organization tab with validation, live
  preview, and per-type 'apply to library' actions

py/services/websocket_progress_callback.py

@@ -21,6 +21,14 @@ class WebSocketProgressCallback(ProgressCallback):
         await ws_manager.broadcast_auto_organize_progress(progress_data)
 
 
+class WebSocketFilenameTemplateProgressCallback(ProgressCallback):
+    """WebSocket progress callback for filename template operations."""
+
+    async def on_progress(self, progress_data: Dict[str, Any]) -> None:
+        """Send filename template progress via WebSocket."""
+        await ws_manager.broadcast_filename_template_progress(progress_data)
+
+
 class WebSocketBroadcastCallback:
     """Generic WebSocket progress callback broadcasting to all clients."""