Add auto-start targets feature with dashboard section

- Add auto_start boolean field to PictureTarget model (persisted per-target)
- Wire auto_start through API schemas, routes, and store
- Auto-start targets on server boot in main.py lifespan
- Add star toggle button on target cards (next to delete button)
- Add auto-start section on dashboard between performance and profiles
- Remove auto-start section from profiles tab

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/storage/wled_picture_target.py

@@ -54,9 +54,9 @@ class WledPictureTarget(PictureTarget):
     def update_fields(self, *, name=None, device_id=None, color_strip_source_id=None,
                       brightness_value_source_id=None,
                       fps=None, keepalive_interval=None, state_check_interval=None,
-                      description=None, **_kwargs) -> None:
+                      description=None, auto_start=None, **_kwargs) -> None:
         """Apply mutable field updates for WLED targets."""
-        super().update_fields(name=name, description=description)
+        super().update_fields(name=name, description=description, auto_start=auto_start)
         if device_id is not None:
             self.device_id = device_id
         if color_strip_source_id is not None:
@@ -109,6 +109,7 @@ class WledPictureTarget(PictureTarget):
             keepalive_interval=data.get("keepalive_interval", data.get("standby_interval", 1.0)),
             state_check_interval=data.get("state_check_interval", DEFAULT_STATE_CHECK_INTERVAL),
             description=data.get("description"),
+            auto_start=data.get("auto_start", False),
             created_at=datetime.fromisoformat(data.get("created_at", datetime.utcnow().isoformat())),
             updated_at=datetime.fromisoformat(data.get("updated_at", datetime.utcnow().isoformat())),
         )