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/build/build.module.ts

@@ -1,5 +1,6 @@
 import { Module, forwardRef } from '@nestjs/common';
 import { BuildService } from './build.service';
+import { ScanService } from './scan.service';
 import { KubernetesModule } from '../kubernetes/kubernetes.module';
 import { ClustersModule } from '../clusters/clusters.module';
 
@@ -8,7 +9,7 @@ import { ClustersModule } from '../clusters/clusters.module';
     forwardRef(() => KubernetesModule),
     ClustersModule,
   ],
-  providers: [BuildService],
-  exports: [BuildService],
+  providers: [BuildService, ScanService],
+  exports: [BuildService, ScanService],
 })
 export class BuildModule {}