feat: Docker self-hosting setup

- Fix Dockerfiles to copy pnpm-lock.yaml (frozen-lockfile compliance)
- Add migrate target to API Dockerfile using builder stage
- Add migrate service to docker-compose that runs before API starts
- Add AUTH_DISABLED env var bypass to auth middleware for dev/Docker
- Proxy /api/ from nginx to API container (no CORS needed)
- Include initial Drizzle migration (0000_colossal_colossus.sql)
- Add .env.example with all configurable variables
- Update README with Docker self-hosting instructions

Closes #7

Co-authored-by: Groom Book CTO <cto@groombook.app>
Co-authored-by: Paperclip <noreply@paperclip.ing>

packages/db/migrations/meta/_journal.json

@@ -0,0 +1,13 @@
+{
+  "version": "7",
+  "dialect": "postgresql",
+  "entries": [
+    {
+      "idx": 0,
+      "version": "7",
+      "when": 1773771452946,
+      "tag": "0000_colossal_colossus",
+      "breakpoints": true
+    }
+  ]
+}