feat(task1): restructure directories for turborepo monorepo

- Move backend/ to apps/server/ via git mv
- Move frontend/ to apps/admin/ via git mv
- Create packages/typescript-config/ with base, nestjs, and react-vite presets

apps/server/src/auth/guards/jwt-auth.guard.ts

@@ -0,0 +1,5 @@
+import { Injectable, ExecutionContext } from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+
+@Injectable()
+export class JwtAuthGuard extends AuthGuard('jwt') {}