feat: add PostgreSQL persistence for permanent shareable links

- Add PostgreSQL service to docker-compose with health checks
- Add migrate service that runs prisma migrate deploy on startup
- Integrate Prisma client in worker: checks for existing generations
  (same repo+commit) before regenerating, writes to Postgres on completion
- Update /api/docs/[id] with Redis → PostgreSQL fallback + cache repopulation
- Update Dockerfile: prisma generate in build, copy Prisma engine to worker/web
- Add @codeboard/database dependency to web and worker packages
- Add initial SQL migration for Generation and User tables
- Change removeOnComplete to { age: 3600 } for job retention

apps/web/next.config.mjs

@@ -1,6 +1,6 @@
 /** @type {import('next').NextConfig} */
 const config = {
-  transpilePackages: ["@codeboard/shared"],
+  transpilePackages: ["@codeboard/shared", "@codeboard/database"],
   output: "standalone",
 };