feat: add daily request limit and refactor access control (#759)

- Add daily request limit per IP in blacklist settings (1-1,000,000/day)
- Refactor access control logic: merge blacklist and rate limit checks
- Remove RATE_LIMIT_API_DAILY_REQUESTS env var, use database config instead
- Move x-custom-auth check earlier in middleware chain
- Add comprehensive English documentation (31 new guide pages)
- Improve code structure and error handling

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

vitepress-docs/docs/en/guide/feature/google-ads.md

@@ -0,0 +1,29 @@
+# Adding Google Ads to Your Website
+
+## Command Line Deployment
+
+Modify the `.env.prod` file
+
+Add the following two variables, refer to [Google AdSense](https://www.google.com/adsense/start/) for specific values
+
+```txt
+VITE_GOOGLE_AD_CLIENT=ca-pub-123456
+VITE_GOOGLE_AD_SLOT=123456
+```
+
+Then execute the following commands to redeploy pages.
+
+```bash
+pnpm build --emptyOutDir
+# For first deployment, you'll be prompted to create a project, fill in production for the production branch
+pnpm run deploy
+```
+
+## GitHub Action Deployment
+
+Modify `FRONTEND_ENV`, add the following two variables, refer to [Google AdSense](https://www.google.com/adsense/start/) for specific values, then redeploy pages.
+
+```txt
+VITE_GOOGLE_AD_CLIENT=ca-pub-123456
+VITE_GOOGLE_AD_SLOT=123456
+```