feat(build): revamp app build pipeline (queue, Nixpacks, MinIO, Trivy, registry GC)

Rework the application build/deploy pipeline for scalability, reproducibility,
and security:

- Build queue: deploys run through a bounded-concurrency Bull queue
  (BUILD_CONCURRENCY, default 3) so concurrent user deploys can't flood the
  cluster with Kaniko jobs. Build state (progress / cancel / session) moves from
  in-memory Maps to Redis, so cancel + live logs work across backend replicas.
- Nixpacks + BYO Dockerfile: code runtimes build via Nixpacks (or the user's own
  Dockerfile when present); the hand-written per-runtime Dockerfile generators
  and runtime auto-detection are removed. WordPress keeps its templated path.
  Build-time mirror env (NIXPACKS_BUILD_ENV) supports the Iran network.
- Source upload to MinIO: archives stream to in-cluster MinIO; build pods pull
  via a presigned URL. Removes the PVC + helper pod + kubectl cp upload path.
- Report-only Trivy scan after build; per-severity summary stored on the
  deployment and shown as a badge in the dashboard. Never gates a deploy.
- Registry GC: a Redis-locked daily job keeps the newest N image tags per app
  (REGISTRY_KEEP_VERSIONS, default 3) and reclaims disk via garbage-collect.
- Hardening: git tokens are delivered via a per-build Secret + git credential
  store instead of being embedded in the clone URL / Job manifest; build timeout
  is configurable.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/kubernetes/kubernetes.module.ts

@@ -3,6 +3,7 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { KubernetesService } from './kubernetes.service';
 import { HelmService } from './helm.service';
 import { RegistryService } from './registry.service';
+import { RegistryGcService } from './registry-gc.service';
 import { ElasticsearchService } from './elasticsearch.service';
 import { ElasticsearchController } from './elasticsearch.controller';
 import { LogsController } from './logs.controller';
@@ -13,7 +14,7 @@ import { Deployment } from '../deployments/entities/deployment.entity';
 @Module({
   imports: [forwardRef(() => ClustersModule), TypeOrmModule.forFeature([Application, Deployment])],
   controllers: [ElasticsearchController, LogsController],
-  providers: [KubernetesService, HelmService, RegistryService, ElasticsearchService],
+  providers: [KubernetesService, HelmService, RegistryService, RegistryGcService, ElasticsearchService],
   exports: [KubernetesService, HelmService, RegistryService, ElasticsearchService],
 })
 export class KubernetesModule {}