feat: Seaca mobile API, enrollment, FCM push and admin UI (0.9.0)

Adds mobile device registration by admin codes, refresh tokens, push channel
in notification policy, and Settings section for managing Seaca clients.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/models/__init__.py

@@ -9,6 +9,10 @@ from app.models.login_attempt import LoginAttempt
 from app.models.ui_settings import UiSettings
 from app.models.event_severity_override import EventSeverityOverride
 from app.models.user import User
+from app.models.mobile_settings import MobileSettings
+from app.models.mobile_enrollment_code import MobileEnrollmentCode
+from app.models.mobile_device import MobileDevice
+from app.models.mobile_refresh_token import MobileRefreshToken
 
 __all__ = [
     "ApiKey",
@@ -23,4 +27,8 @@ __all__ = [
     "EventSeverityOverride",
     "LoginAttempt",
     "UiSettings",
+    "MobileSettings",
+    "MobileEnrollmentCode",
+    "MobileDevice",
+    "MobileRefreshToken",
 ]