feat(server): add Swagger API docs (#13455)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Interactive API documentation available at /api/docs when running in
development.

* **Chores**
* Added a development dependency to enable generation of the API
documentation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: DarkSky <25152247+darkskygit@users.noreply.github.com>
Co-authored-by: DarkSky <darksky2048@gmail.com>

packages/backend/server/package.json

@@ -128,6 +128,7 @@
     "@affine-tools/utils": "workspace:*",
     "@affine/graphql": "workspace:*",
     "@faker-js/faker": "^10.0.0",
+    "@nestjs/swagger": "^11.2.0",
     "@nestjs/testing": "patch:@nestjs/testing@npm%3A10.4.15#~/.yarn/patches/@nestjs-testing-npm-10.4.15-d591a1705a.patch",
     "@types/cookie-parser": "^1.4.8",
     "@types/express": "^5.0.1",

packages/backend/server/src/server.ts

@@ -59,6 +59,21 @@ export async function run() {
   const adapter = new SocketIoAdapter(app);
   app.useWebSocketAdapter(adapter);
 
+  if (env.dev) {
+    const { SwaggerModule, DocumentBuilder } = await import('@nestjs/swagger');
+    // Swagger API Docs
+    const docConfig = new DocumentBuilder()
+      .setTitle('AFFiNE API')
+      .setDescription(`AFFiNE Server ${env.version} API documentation`)
+      .setVersion(`${env.version}`)
+      .build();
+    const documentFactory = () => SwaggerModule.createDocument(app, docConfig);
+    SwaggerModule.setup('/api/docs', app, documentFactory, {
+      useGlobalPrefix: true,
+      swaggerOptions: { persistAuthorization: true },
+    });
+  }
+
   const url = app.get(URLHelper);
   const listeningHost = '0.0.0.0';