Scaffold HIPCTF platform (NestJS + Angular)

- Backend: NestJS 10 + TypeORM (better-sqlite3) feature-modular layout.
  - Entities: user, setting, category, challenge, challenge_file, solve,
    refresh_token, blog_post. Auto-run migrations + idempotent 6-system-
    category seed on startup.
  - Argon2id password hashing with policy check; JWT access + rotating
    refresh tokens (HttpOnly cookie); CSRF middleware (SameSite + custom
    X-CSRF-Token header); global JWT auth guard with @Public() opt-out;
    per-IP login backoff + per-IP registration rate limit.
  - Endpoints: auth (login/refresh/logout/csrf), users (first-admin
    registration), system (bootstrap/event status/SSE), admin (guarded
    user CRUD with last-admin invariant), frontend module (uploads +
    SPA fallback).
  - Security: helmet+CSP+HSTS-gated-by-TLS, CORS allowlist, structured
    global exception filter, Zod request validation pipes, OpenAPI 3.1
    served at /api/docs and /api/docs-json, 10 canonical themes under
    backend/themes/.
- Frontend: Angular 17 standalone components, lazy-loaded feature routes,
  signals, functional HttpInterceptorFn (csrf + auth), functional
  CanActivateFn auth guard, HttpOnly-cookie-based auth service.
- Tests: Jest + supertest, 46 tests across 13 suites covering
  migrations, env schema, theme loader, event status, login backoff,
  registration rate limit, ApiError shape, bootstrap integration,
  auth refresh rotation, admin guard, last-admin invariant, SSE flat
  payloads. Single-command runner: `npm test`.

backend/src/frontend/uploads-static.middleware.ts

@@ -0,0 +1,22 @@
+import { Injectable, NestMiddleware } from '@nestjs/common';
+import { Request, Response, NextFunction } from 'express';
+import * as fs from 'fs';
+import * as path from 'path';
+import { ConfigService } from '@nestjs/config';
+
+@Injectable()
+export class UploadsStaticMiddleware implements NestMiddleware {
+  private rootDir = '/tmp';
+
+  constructor(config: ConfigService) {
+    const dir = path.resolve(config.get<string>('UPLOAD_DIR', '/data/hipctf/uploads'));
+    if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
+    this.rootDir = dir;
+  }
+
+  use(req: Request, res: Response, next: NextFunction): void {
+    if (!req.path.startsWith('/uploads')) return next();
+    const express = require('express');
+    return express.static(this.rootDir)(req, res, next);
+  }
+}