feat: add access profile selection support with device-specific profile persistence

Add SelectOwnProfile handler to allow users to choose from available access profiles. Store selected profile ID per device in settings table with device_access_profile category. Implement GetSelectedProfileID and SetSelectedProfileID repository methods using JSONB storage.

Add ListSelectableProfiles to policy repository and service to query user/group/device-specific profiles ordered by priority. Filter gateway

backend/internal/policy/service.go

@@ -39,3 +39,7 @@ func (s *Service) Delete(ctx context.Context, policyID uuid.UUID) error {
 func (s *Service) ResolveDestinations(ctx context.Context, userID uuid.UUID, deviceID *uuid.UUID) ([]string, error) {
 	return s.repo.ResolveDestinations(ctx, userID, deviceID)
 }
+
+func (s *Service) ListSelectableProfiles(ctx context.Context, userID uuid.UUID, deviceID *uuid.UUID) ([]SelectableProfile, error) {
+	return s.repo.ListSelectableProfiles(ctx, userID, deviceID)
+}