fix: reliable source upload, build cancel, WordPress port 80 default

- Replace port-forward/netcat PVC upload with kubectl cp for integrity
- Add build cancellation API and session cleanup; deploy catches cancel
- Default port 80 for WordPress, PHP, and Laravel on create
- Build progress modal with cancel; Helm/K8s adjustments for deployments
- Update build and kubernetes specs

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

backend/src/kubernetes/kubernetes.service.spec.ts

@@ -50,7 +50,6 @@ describe('buildHelmValues logic', () => {
       },
       wordpress: {
         enabled: isWordPress,
-        wpContentStorageSize: '2Gi',
       },
       changeCause: `Deploy ${imageUri} at 2024-01-01T00:00:00.000Z`,
     };