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/app.module.ts

@@ -15,8 +15,6 @@ import { SnapshotsModule } from './snapshots/snapshots.module';
 import { LifecycleModule } from './lifecycle/lifecycle.module';
 import { ApplicationMigrationsModule } from './application-migrations/application-migrations.module';
 import { AdminModule } from './admin/admin.module';
-import { RedisModule } from './common/redis/redis.module';
-import { StorageModule } from './common/storage/storage.module';
 import configuration from './config/configuration';
 
 @Module({
@@ -56,12 +54,6 @@ import configuration from './config/configuration';
       inject: [ConfigService],
     }),
 
-    // Shared Redis client (build state across replicas)
-    RedisModule,
-
-    // Shared MinIO storage (application source archives)
-    StorageModule,
-
     // Feature modules
     AuthModule,
     UsersModule,