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/postprocessing.py

@@ -50,6 +50,7 @@ def _pp_template_to_response(t) -> PostprocessingTemplateResponse:
         created_at=t.created_at,
         updated_at=t.updated_at,
         description=t.description,
+        tags=getattr(t, 'tags', []),
     )
 
 
@@ -81,6 +82,7 @@ async def create_pp_template(
             name=data.name,
             filters=filters,
             description=data.description,
+            tags=data.tags,
         )
         return _pp_template_to_response(template)
     except ValueError as e:
@@ -119,6 +121,7 @@ async def update_pp_template(
             name=data.name,
             filters=filters,
             description=data.description,
+            tags=data.tags,
         )
         return _pp_template_to_response(template)
     except ValueError as e: