revert: remove unused Agent PostgreSQL persistence

package.json

@@ -11,18 +11,15 @@
     "dev": "bun --watch src/server.ts",
     "build": "bun run check",
     "check": "bun run typecheck && bun run typecheck:opencode",
-    "migrate:storage": "bun scripts/migrate-file-storage-to-postgres.ts",
     "pipeline:trigger": "bash scripts/trigger-gitea-pipeline.sh",
     "start": "bun src/server.ts",
     "start:prod": "bun run check && bun src/server.ts"
   },
   "dependencies": {
     "@opencode-ai/sdk": "^1.14.29",
-    "@types/pg": "^8.20.0",
     "cors": "^2.8.5",
     "dotenv": "^17.2.3",
     "express": "^4.21.2",
-    "pg": "^8.21.0",
     "pino": "^9.7.0",
     "pino-pretty": "^13.1.2",
     "zod": "^3.25.76"