Add MDI icon picker to all entity types

- Install @mdi/js (~7000 Material Design Icons)
- IconPicker component: dropdown with search, popular icons grid,
  clear option. Stores icon name as string (e.g. "mdiCamera")
- MdiIcon component: renders SVG from icon name
- Backend: add `icon` field to ImmichServer, TelegramBot,
  TrackingConfig, TemplateConfig, NotificationTarget, AlbumTracker
- All 6 entity pages: icon picker next to name input in create/edit
  forms, icon displayed on entity cards

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/server/src/immich_watcher_server/database/models.py

@@ -33,6 +33,7 @@ class ImmichServer(SQLModel, table=True):
     url: str
     api_key: str
     external_domain: str | None = None
+    icon: str = Field(default="")  # MDI icon name (e.g. "mdiServer")
     created_at: datetime = Field(default_factory=_utcnow)
 
 
@@ -45,6 +46,7 @@ class TelegramBot(SQLModel, table=True):
     user_id: int = Field(foreign_key="user.id")
     name: str  # User-given display name
     token: str  # Bot API token
+    icon: str = Field(default="")  # MDI icon name
     bot_username: str = Field(default="")  # @username from getMe
     bot_id: int = Field(default=0)  # Numeric bot ID from getMe
     created_at: datetime = Field(default_factory=_utcnow)
@@ -58,6 +60,7 @@ class TrackingConfig(SQLModel, table=True):
     id: int | None = Field(default=None, primary_key=True)
     user_id: int = Field(foreign_key="user.id")
     name: str
+    icon: str = Field(default="")
 
     # Event-driven tracking
     track_assets_added: bool = Field(default=True)
@@ -112,6 +115,7 @@ class TemplateConfig(SQLModel, table=True):
     id: int | None = Field(default=None, primary_key=True)
     user_id: int = Field(foreign_key="user.id")
     name: str  # e.g. "Default EN", "Default RU"
+    icon: str = Field(default="")
 
     # Event messages
     message_assets_added: str = Field(
@@ -172,6 +176,7 @@ class NotificationTarget(SQLModel, table=True):
     user_id: int = Field(foreign_key="user.id")
     type: str  # "telegram" or "webhook"
     name: str
+    icon: str = Field(default="")
     config: dict[str, Any] = Field(default_factory=dict, sa_column=Column(JSON))
     tracking_config_id: int | None = Field(default=None, foreign_key="tracking_config.id")
     template_config_id: int | None = Field(default=None, foreign_key="template_config.id")
@@ -187,6 +192,7 @@ class AlbumTracker(SQLModel, table=True):
     user_id: int = Field(foreign_key="user.id")
     server_id: int = Field(foreign_key="immich_server.id")
     name: str
+    icon: str = Field(default="")
     album_ids: list[str] = Field(default_factory=list, sa_column=Column(JSON))
     target_ids: list[int] = Field(default_factory=list, sa_column=Column(JSON))
     scan_interval: int = Field(default=60)