revert(build): remove app build pipeline revamp (Nixpacks/MinIO/Trivy/registry GC)

Reverts commits 3eff38f and c379a23 and restores the previous Kaniko-only
build pipeline (runtime detection + per-runtime Dockerfile generation,
disk-based source upload).

Removed: Nixpacks Dockerfile generation, MinIO source storage (common/storage),
Bull build queue + Redis build state (common/redis, deployment.processor),
Trivy image scan (scan.service, deployment.vulnerabilitySummary), and daily
registry garbage collection (registry-gc). Nothing outside the build/deploy
path depended on these. Backend tsc + 105/106 tests green (the pre-existing
helm.service chartPath failure is unrelated); frontend tsc green.

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

backend/src/config/configuration.ts

@@ -125,45 +125,9 @@ export default () => ({
     password: process.env.REGISTRY_PASSWORD || '',
   },
 
-  // In-cluster MinIO (S3-compatible) for application source archives.
-  minio: {
-    endpoint: process.env.MINIO_ENDPOINT || 'minio.cloudhost-builds.svc.cluster.local',
-    port: parseInt(process.env.MINIO_PORT || '9000', 10),
-    useSSL: process.env.MINIO_USE_SSL === 'true',
-    accessKey: process.env.MINIO_ACCESS_KEY || 'cloudhost',
-    secretKey: process.env.MINIO_SECRET_KEY || 'CloudHost2024!Minio',
-    bucket: process.env.MINIO_BUCKET || 'app-sources',
-  },
-
   build: {
     namespace: process.env.BUILD_NAMESPACE || 'cloudhost-builds',
     serviceAccount: process.env.BUILD_SERVICE_ACCOUNT || 'kaniko-builder',
-    /** Max number of build+deploy pipelines processed concurrently across the queue. */
-    concurrency: parseInt(process.env.BUILD_CONCURRENCY || '3', 10),
-    /** Per-image-build timeout (Kaniko job) in seconds. */
-    timeoutSeconds: parseInt(process.env.BUILD_TIMEOUT_SECONDS || '600', 10),
-    /** Nixpacks builder image used to generate a Dockerfile for code runtimes. */
-    nixpacksImage: process.env.NIXPACKS_IMAGE || 'ghcr.io/railwayapp/nixpacks:latest',
-    /**
-     * Build-time env baked into Nixpacks-generated images (mirrors/proxies for the
-     * Iran network, e.g. "NPM_CONFIG_REGISTRY=https://registry.npmmirror.com").
-     * Comma-separated KEY=VALUE pairs — set per the Phase 0 spike findings.
-     */
-    nixpacksBuildEnv: (process.env.NIXPACKS_BUILD_ENV || '')
-      .split(',')
-      .map((s) => s.trim())
-      .filter(Boolean),
-    /** Report-only Trivy image scan after a successful build. */
-    scanEnabled: process.env.BUILD_SCAN_ENABLED !== 'false',
-    trivyImage: process.env.TRIVY_IMAGE || 'aquasec/trivy:latest',
-    /** Optional mirror for Trivy's vulnerability DB (Iran network); empty = default ghcr.io. */
-    trivyDbRepository: process.env.TRIVY_DB_REPOSITORY || '',
-    /** Max seconds to wait for the Trivy scan job. */
-    scanTimeoutSeconds: parseInt(process.env.BUILD_SCAN_TIMEOUT_SECONDS || '300', 10),
-    /** Registry garbage collection: keep the N most recent image tags per app repo. */
-    registryGcEnabled: process.env.REGISTRY_GC_ENABLED !== 'false',
-    registryKeepVersions: parseInt(process.env.REGISTRY_KEEP_VERSIONS || '3', 10),
-    registryGcIntervalMs: parseInt(process.env.REGISTRY_GC_INTERVAL_MS || '86400000', 10), // daily
   },
 
   elasticsearch: {