feat(v3.13.0): settings live DB reads, remove Directus/Appwrite, admin stats

Settings fixes:
- MAX_SITES_PER_USER, USER_RATE_LIMIT_PER_MIN/HR now read from DB settings
  table (DB > ENV > default), so dashboard/settings changes apply without
  restart. Sync cache refreshed on every save or delete.
- /api/me reports the live DB value for max_sites_per_user.

Admin improvements:
- Admin users bypass per-user rate limiting entirely (role=admin or ADMIN_EMAILS).
- Admin Overview now shows platform stats: registered users, new users (7d),
  total user sites, available tools.

Plugin cleanup:
- Appwrite and Directus plugins removed from the active registry (8 plugins
  now: WordPress, WooCommerce, WordPress Specialist, Gitea, n8n, Supabase,
  OpenPanel, Coolify). Plugin code is retained for future re-enabling.
- Settings page plugin visibility list updated to match.

Mobile onboarding:
- Stepper steps on narrow viewports stack vertically with correct full border
  and rounded corners on each step.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/wordpress/schemas/__init__.py

@@ -30,7 +30,8 @@ from plugins.wordpress.schemas.product import (
 )
 from plugins.wordpress.schemas.seo import SEOData, SEOUpdate
 
-# Note: Database, Bulk, and System schemas moved to wordpress_advanced plugin
+# Database / bulk / system schemas live on wordpress_specialist
+# (companion-backed; legacy wordpress_advanced was sunset 2026-05-04).
 
 __all__ = [
     # Common
@@ -64,5 +65,4 @@ __all__ = [
     # SEO
     "SEOData",
     "SEOUpdate",
-    # Note: Database, Bulk, and System schemas moved to wordpress_advanced plugin
 ]