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_specialist/__init__.py

@@ -0,0 +1,17 @@
+"""WordPress Specialist Plugin (F.19).
+
+Companion-backed advanced WordPress management for professionals —
+plugins, themes, users, options, cron, maintenance, page editing, site
+config + layout, db inspection, bulk fan-out. Replaced the deprecated
+``wordpress_advanced`` plugin (sunset 2026-05-04 in F.19.3.2-.3); this
+plugin requires only Airano MCP Bridge v2.18.0+ and an Application
+Password for a user with ``manage_options``. No Docker socket needed.
+"""
+
+from plugins.wordpress_specialist import handlers
+from plugins.wordpress_specialist.plugin import WordPressSpecialistPlugin
+
+__all__ = [
+    "WordPressSpecialistPlugin",
+    "handlers",
+]