feat: scaffold center and guild backend NestJS skeletons

Fabric.Backend.Center/src/auth/auth.controller.ts

@@ -0,0 +1,19 @@
+import { Body, Controller, Post } from '@nestjs/common';
+
+@Controller('auth')
+export class AuthController {
+  @Post('register')
+  register(@Body() body: Record<string, unknown>) {
+    return { status: 'todo', action: 'register', received: body };
+  }
+
+  @Post('login')
+  login(@Body() body: Record<string, unknown>) {
+    return { status: 'todo', action: 'login', received: body };
+  }
+
+  @Post('refresh')
+  refresh(@Body() body: Record<string, unknown>) {
+    return { status: 'todo', action: 'refresh', received: body };
+  }
+}