Fix Passenger ESM incompatibility — add server.cjs CJS wrapper

Passenger's node-loader uses require() which cannot load ES modules.
server.cjs is a CommonJS shim that bridges into server.js via dynamic import().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -16,7 +16,7 @@
     "dev:api": "npm run dev -w apps/api",
     "build": "npm run build -w apps/web",
     "build:check": "npm run build && npm run typecheck",
-    "start": "node server.js",
+    "start": "node server.cjs",
     "db:generate": "npm run generate -w packages/db",
     "db:migrate": "npm run migrate -w packages/db",
     "typecheck": "npm run typecheck --workspaces --if-present"