Security audit fixes, mobile responsiveness across 40+ admin pages

Security hardening from Mar 31 audit:
- Separate login rate limit (10/15min) from general auth budget (15/15min)
- Timing-safe webhook secret comparison (Listmonk)
- Docs file creation ACL check (matches PUT/DELETE guards)
- Key separation warnings for GITEA_SSO_SECRET and SERVICE_PASSWORD_SALT
- Clear GITEA_ADMIN_PASSWORD from .env after auto-setup
- SQL injection prevention in effectiveness groupBy (pre-validated map)
- Token hashing for password reset and verification tokens

Mobile responsiveness (Phase 2C):
- Add MobilePageHeader component and useMobile hook
- Responsive table columns (hide secondary cols on mobile)
- scroll={{ x: 'max-content' }} across all data tables
- Mobile-adapted layouts for Dashboard, Settings, Calendar, SMS, Social pages
- Conditional toolbar buttons on mobile viewports

Infrastructure:
- Updated docker-compose and nginx templates
- Build script and mirror script updates

Bunker Admin

nginx/conf.d/api.conf.template

@@ -26,6 +26,19 @@ server {
         proxy_set_header Connection "upgrade";
     }
 
+    # Auth endpoints — stricter rate limit to prevent credential stuffing
+    location /api/auth/ {
+        limit_req zone=api_auth burst=10 nodelay;
+        set $upstream_api http://changemaker-v2-api:4000;
+        proxy_pass $upstream_api;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $remote_addr;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_read_timeout 300s;
+        proxy_connect_timeout 75s;
+    }
+
     # Main API (Express)
     location / {
         limit_req zone=api_global burst=60 nodelay;