Add tags to all entity types with chip-based input and autocomplete

- Add `tags: List[str]` field to all 13 entity types (devices, output targets,
  CSS sources, picture sources, audio sources, value sources, sync clocks,
  automations, scene presets, capture/audio/PP/pattern templates)
- Update all stores, schemas, and route handlers for tag CRUD
- Add GET /api/v1/tags endpoint aggregating unique tags across all stores
- Create TagInput component with chip display, autocomplete dropdown,
  keyboard navigation, and API-backed suggestions
- Display tag chips on all entity cards (searchable via existing text filter)
- Add tag input to all 14 editor modals with dirty check support
- Add CSS styles and i18n keys (en/ru/zh) for tag UI
- Also includes code review fixes: thread safety, perf, store dedup

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/api/routes/picture_sources.py

@@ -60,6 +60,7 @@ def _stream_to_response(s) -> PictureSourceResponse:
         created_at=s.created_at,
         updated_at=s.updated_at,
         description=s.description,
+        tags=getattr(s, 'tags', []),
     )
 
 
@@ -196,6 +197,7 @@ async def create_picture_source(
             postprocessing_template_id=data.postprocessing_template_id,
             image_source=data.image_source,
             description=data.description,
+            tags=data.tags,
         )
         return _stream_to_response(stream)
     except HTTPException:
@@ -240,6 +242,7 @@ async def update_picture_source(
             postprocessing_template_id=data.postprocessing_template_id,
             image_source=data.image_source,
             description=data.description,
+            tags=data.tags,
         )
         return _stream_to_response(stream)
     except ValueError as e: