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/audio_source.py

@@ -5,9 +5,9 @@ An AudioSource represents a reusable audio input configuration:
   MonoAudioSource          — extracts a single channel from a multichannel source
 """
 
-from dataclasses import dataclass
-from datetime import datetime
-from typing import Optional
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from typing import List, Optional
 
 
 @dataclass
@@ -20,6 +20,7 @@ class AudioSource:
     created_at: datetime
     updated_at: datetime
     description: Optional[str] = None
+    tags: List[str] = field(default_factory=list)
 
     def to_dict(self) -> dict:
         """Convert source to dictionary. Subclasses extend this."""
@@ -30,6 +31,7 @@ class AudioSource:
             "created_at": self.created_at.isoformat(),
             "updated_at": self.updated_at.isoformat(),
             "description": self.description,
+            "tags": self.tags,
             # Subclass fields default to None for forward compat
             "device_index": None,
             "is_loopback": None,
@@ -45,26 +47,27 @@ class AudioSource:
         sid: str = data["id"]
         name: str = data["name"]
         description: str | None = data.get("description")
+        tags: list = data.get("tags", [])
 
         raw_created = data.get("created_at")
         created_at: datetime = (
             datetime.fromisoformat(raw_created)
             if isinstance(raw_created, str)
             else raw_created if isinstance(raw_created, datetime)
-            else datetime.utcnow()
+            else datetime.now(timezone.utc)
         )
         raw_updated = data.get("updated_at")
         updated_at: datetime = (
             datetime.fromisoformat(raw_updated)
             if isinstance(raw_updated, str)
             else raw_updated if isinstance(raw_updated, datetime)
-            else datetime.utcnow()
+            else datetime.now(timezone.utc)
         )
 
         if source_type == "mono":
             return MonoAudioSource(
                 id=sid, name=name, source_type="mono",
-                created_at=created_at, updated_at=updated_at, description=description,
+                created_at=created_at, updated_at=updated_at, description=description, tags=tags,
                 audio_source_id=data.get("audio_source_id") or "",
                 channel=data.get("channel") or "mono",
             )
@@ -72,7 +75,7 @@ class AudioSource:
         # Default: multichannel
         return MultichannelAudioSource(
             id=sid, name=name, source_type="multichannel",
-            created_at=created_at, updated_at=updated_at, description=description,
+            created_at=created_at, updated_at=updated_at, description=description, tags=tags,
             device_index=int(data.get("device_index", -1)),
             is_loopback=bool(data.get("is_loopback", True)),
             audio_template_id=data.get("audio_template_id"),