feat: automatic deploy system (poll+deploy docker stack on Unraid)

- deployer container polls git, builds api/worker/web, runs migrations+seed,
  starts ff-api/ff-worker/ff-web + nginx TLS reverse proxy against external
  Postgres (10.0.0.15)
- Dockerfile.web: drop missing packages/ui package, add NEXT_PUBLIC_API_URL arg
- add root .dockerignore (build context cleanup)

.dockerignore

@@ -0,0 +1,16 @@
+.git
+.gitignore
+**/node_modules
+**/dist
+**/.next
+**/*.tsbuildinfo
+*.log
+.env
+.env.*
+infrastructure/certs
+infrastructure/agent-releases
+infrastructure/software-releases
+agents/forge-agent/forge-agent
+apps/web/.env*
+.turbo
+pnpm-debug.log*