feat: project-scoped Docker image prune, conflict fix, deploy toggle, access list picker

- Image prune only removes images matching project image refs, skips active instances
- Add ListImagesByRef and RemoveImage to Docker client
- Fix 409 conflict: use listProjects instead of duplicate POST
- Add "Deploy immediately" toggle to Quick Deploy (off by default)
- Replace raw access list ID with EntityPicker on project edit form
- Trigger proxy resync on access list change
- Fix stage form layout: single responsive row
- Fix empty port default on project creation
- Improve inspect error message for remote Docker

internal/api/router.go

@@ -308,6 +308,9 @@ func (s *Server) Router() chi.Router {
 				r.Get("/settings/webhook-url", s.getWebhookURL)
 				r.Post("/settings/webhook-url/regenerate", s.regenerateWebhookSecret)
 
+				// Docker management.
+				r.Post("/docker/prune-images", s.pruneImages)
+
 				// NPM connection test.
 				r.Post("/settings/npm/test", s.testNpmConnection)