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/base_store.py

@@ -0,0 +1,115 @@
+"""Base class for JSON entity stores — eliminates boilerplate across 12+ stores."""
+
+import json
+from pathlib import Path
+from typing import Callable, Dict, Generic, List, TypeVar
+
+from wled_controller.utils import atomic_write_json, get_logger
+
+T = TypeVar("T")
+logger = get_logger(__name__)
+
+
+class BaseJsonStore(Generic[T]):
+    """JSON-file-backed entity store with common CRUD helpers.
+
+    Provides:
+    - ``_load()`` / ``_save()``: atomic JSON file I/O
+    - ``get_all()`` / ``get(id)`` / ``delete(id)`` / ``count()``: read/delete
+    - ``_check_name_unique(name, exclude_id)``: duplicate-name guard
+
+    Subclasses must set class attributes:
+    - ``_json_key``:     root key in JSON file (e.g. ``"sync_clocks"``)
+    - ``_entity_name``:  human label for errors (e.g. ``"Sync clock"``)
+    - ``_version``:      schema version string (default ``"1.0.0"``)
+    """
+
+    _json_key: str
+    _entity_name: str
+    _version: str = "1.0.0"
+
+    def __init__(self, file_path: str, deserializer: Callable[[dict], T]):
+        self.file_path = Path(file_path)
+        self._items: Dict[str, T] = {}
+        self._deserializer = deserializer
+        self._load()
+
+    # ── I/O ────────────────────────────────────────────────────────
+
+    def _load(self) -> None:
+        if not self.file_path.exists():
+            logger.info(f"{self._entity_name} store file not found — starting empty")
+            return
+
+        try:
+            with open(self.file_path, "r", encoding="utf-8") as f:
+                data = json.load(f)
+
+            items_data = data.get(self._json_key, {})
+            loaded = 0
+            for item_id, item_dict in items_data.items():
+                try:
+                    self._items[item_id] = self._deserializer(item_dict)
+                    loaded += 1
+                except Exception as e:
+                    logger.error(
+                        f"Failed to load {self._entity_name} {item_id}: {e}",
+                        exc_info=True,
+                    )
+
+            if loaded > 0:
+                logger.info(f"Loaded {loaded} {self._json_key} from storage")
+
+        except Exception as e:
+            logger.error(f"Failed to load {self._json_key} from {self.file_path}: {e}")
+            raise
+
+        logger.info(
+            f"{self._entity_name} store initialized with {len(self._items)} items"
+        )
+
+    def _save(self) -> None:
+        try:
+            data = {
+                "version": self._version,
+                self._json_key: {
+                    item_id: item.to_dict()
+                    for item_id, item in self._items.items()
+                },
+            }
+            atomic_write_json(self.file_path, data)
+        except Exception as e:
+            logger.error(f"Failed to save {self._json_key} to {self.file_path}: {e}")
+            raise
+
+    # ── Common CRUD ────────────────────────────────────────────────
+
+    def get_all(self) -> List[T]:
+        return list(self._items.values())
+
+    def get(self, item_id: str) -> T:
+        if item_id not in self._items:
+            raise ValueError(f"{self._entity_name} not found: {item_id}")
+        return self._items[item_id]
+
+    def delete(self, item_id: str) -> None:
+        if item_id not in self._items:
+            raise ValueError(f"{self._entity_name} not found: {item_id}")
+        del self._items[item_id]
+        self._save()
+        logger.info(f"Deleted {self._entity_name}: {item_id}")
+
+    def count(self) -> int:
+        return len(self._items)
+
+    # ── Helpers ────────────────────────────────────────────────────
+
+    def _check_name_unique(self, name: str, exclude_id: str = None) -> None:
+        """Raise ValueError if *name* is empty or already taken."""
+        if not name or not name.strip():
+            raise ValueError("Name is required")
+        for item_id, item in self._items.items():
+            if item_id != exclude_id and getattr(item, "name", None) == name:
+                raise ValueError(
+                    f"{self._entity_name} with name '{name}' already exists"
+                )