feat: add startup migration script and improve Docker setup

- Add scripts/start.ts to run drizzle migrations before server start
- Update Dockerfile to copy migration files and install prod deps
- Change entrypoint to use migration-aware startup script
- Add deployment documentation

Dockerfile

@@ -20,6 +20,19 @@ WORKDIR /app
 # Only `.output` folder is needed from the build stage
 COPY --from=build /app/.output /app
 
+# Copy migration SQL files for runtime migrations
+COPY --from=build /app/drizzle/migrations /app/drizzle/migrations
+
+# Copy entrypoint script
+COPY --from=build /app/scripts/start.ts /app/scripts/start.ts
+
+# Copy package.json and lockfile for production dependency install
+COPY --from=build /app/package.json /app/package.json
+COPY --from=build /app/bun.lock* ./
+
+# Install production dependencies only (drizzle-orm, pg, etc.)
+RUN bun install --frozen-lockfile --production --ignore-scripts
+
 # run the app
 EXPOSE 3000/tcp
-ENTRYPOINT [ "bun", "--bun", "run", "/app/server/index.mjs" ]
+ENTRYPOINT [ "bun", "run", "/app/scripts/start.ts" ]