fix: quick deploy duplicate detection, logout UX, backup toggle, CSP, SSE guard, and migration

- Detect existing projects with same image on quick deploy; show conflict dialog with options
- Move logout button to sidebar header as icon-only
- Replace backup checkbox with ToggleSwitch component
- Allow unsafe-inline in CSP script-src for SvelteKit hydration
- Guard SSE connection behind isAuthenticated() check
- Add notification_url ALTER TABLE migration for existing databases
- Restore RegisterPersistentLogger on event bus

internal/store/projects.go

@@ -63,6 +63,28 @@ func (s *Store) GetAllProjects() ([]Project, error) {
 	return projects, rows.Err()
 }
 
+// GetProjectsByImage returns all projects using the given image, newest first.
+func (s *Store) GetProjectsByImage(image string) ([]Project, error) {
+	rows, err := s.db.Query(
+		`SELECT id, name, registry, image, port, healthcheck, env, volumes, created_at, updated_at
+		 FROM projects WHERE image = ? ORDER BY created_at DESC`, image,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("query projects by image: %w", err)
+	}
+	defer rows.Close()
+
+	projects := []Project{}
+	for rows.Next() {
+		var p Project
+		if err := rows.Scan(&p.ID, &p.Name, &p.Registry, &p.Image, &p.Port, &p.Healthcheck, &p.Env, &p.Volumes, &p.CreatedAt, &p.UpdatedAt); err != nil {
+			return nil, fmt.Errorf("scan project: %w", err)
+		}
+		projects = append(projects, p)
+	}
+	return projects, rows.Err()
+}
+
 // UpdateProject updates an existing project's mutable fields.
 func (s *Store) UpdateProject(p Project) error {
 	p.UpdatedAt = Now()