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/storage/automation.py

@@ -1,7 +1,7 @@
 """Automation and Condition data models."""
 
 from dataclasses import dataclass, field
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import List, Optional
 
 
@@ -204,6 +204,7 @@ class Automation:
     deactivation_scene_preset_id: Optional[str]  # scene for fallback_scene mode
     created_at: datetime
     updated_at: datetime
+    tags: List[str] = field(default_factory=list)
 
     def to_dict(self) -> dict:
         return {
@@ -215,6 +216,7 @@ class Automation:
             "scene_preset_id": self.scene_preset_id,
             "deactivation_mode": self.deactivation_mode,
             "deactivation_scene_preset_id": self.deactivation_scene_preset_id,
+            "tags": self.tags,
             "created_at": self.created_at.isoformat(),
             "updated_at": self.updated_at.isoformat(),
         }
@@ -237,6 +239,7 @@ class Automation:
             scene_preset_id=data.get("scene_preset_id"),
             deactivation_mode=data.get("deactivation_mode", "none"),
             deactivation_scene_preset_id=data.get("deactivation_scene_preset_id"),
-            created_at=datetime.fromisoformat(data.get("created_at", datetime.utcnow().isoformat())),
-            updated_at=datetime.fromisoformat(data.get("updated_at", datetime.utcnow().isoformat())),
+            tags=data.get("tags", []),
+            created_at=datetime.fromisoformat(data.get("created_at", datetime.now(timezone.utc).isoformat())),
+            updated_at=datetime.fromisoformat(data.get("updated_at", datetime.now(timezone.utc).isoformat())),
         )