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

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

vitepress-docs/docs/en/guide/feature/admin-user-management.md

@@ -0,0 +1,11 @@
+# Admin User Management
+
+## User Management Page
+
+![admin-user-management](/feature/admin-user-management.png)
+
+## User Settings
+
+Configure user login and authentication settings here
+
+![admin-user-page](/feature/admin-user-page.png)