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>

frontend/src/types/index.ts

@@ -159,17 +159,6 @@ export interface Deployment {
   triggeredBy: string;
   createdAt: string;
   finishedAt?: string;
-  vulnerabilitySummary?: VulnerabilitySummary | null;
-}
-
-export interface VulnerabilitySummary {
-  critical: number;
-  high: number;
-  medium: number;
-  low: number;
-  unknown: number;
-  total: number;
-  scannedAt: string;
 }
 
 export type DeploymentStatus =