build: ship pre-built API bundle; images copy output instead of installing

- API: `pnpm build` bundles dist/ into apps/api/.output (esbuild), with
  Linux musl native packages for sharp and argon2 kept alongside
- docker/api.Dockerfile copies that output; no pnpm install on the server
- add dist/migrate.js (prisma migrate deploy equivalent, same
  _prisma_migrations table and lock) so the Prisma CLI is not needed at runtime
- pnpm-workspace: supportedArchitectures for linux/x64/musl
- admin: apps/admin/.env.production sets VITE_SITE_URL for the production build
- drop NPM_REGISTRY / SITE_URL build args from compose and .env.example
- gitignore: anchor node_modules rules so pre-built node_modules are committed
- README: describe the pre-built deploy flow

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

apps/api/.output/node_modules/sharp/install/build.js

@@ -0,0 +1,38 @@
+/*!
+  Copyright 2013 Lovell Fuller and others.
+  SPDX-License-Identifier: Apache-2.0
+*/
+
+const {
+  useGlobalLibvips,
+  globalLibvipsVersion,
+  log,
+  spawnRebuild,
+} = require('../dist/libvips.cjs');
+
+log('Building from source');
+log('See https://sharp.pixelplumbing.com/install#building-from-source');
+
+try {
+  const addonApi = require('node-addon-api');
+  log(`Found node-addon-api ${addonApi.version || ''}`);
+} catch (_err) {
+  log('Please add node-addon-api to your dependencies');
+  process.exit(1);
+}
+try {
+  const gyp = require('node-gyp');
+  log(`Found node-gyp ${gyp().version}`);
+} catch (_err) {
+  log('Please add node-gyp to your dependencies');
+  process.exit(1);
+}
+
+if (useGlobalLibvips(log)) {
+  log(`Found globally-installed libvips v${globalLibvipsVersion()}`);
+}
+
+const status = spawnRebuild();
+if (status !== 0) {
+  process.exit(status);
+}