feat: Dashboard redesign, plan permissions, and help docs improvements

Major updates including:
- Customizable dashboard with drag-and-drop widget grid layout
- Plan-based feature locking for plugins and tasks
- Comprehensive help documentation updates across all pages
- Plugin seeding in deployment process for all tenants
- Permission synchronization system for subscription plans
- QuotaOverageModal component and enhanced UX flows

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

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

frontend/package.json

@@ -11,6 +11,7 @@
     "@stripe/react-stripe-js": "^5.4.1",
     "@stripe/stripe-js": "^8.5.3",
     "@tanstack/react-query": "^5.90.10",
+    "@types/react-grid-layout": "^1.3.6",
     "@types/react-syntax-highlighter": "^15.5.13",
     "axios": "^1.13.2",
     "date-fns": "^4.1.0",
@@ -21,6 +22,7 @@
     "lucide-react": "^0.554.0",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "react-grid-layout": "^1.5.2",
     "react-hot-toast": "^2.6.0",
     "react-i18next": "^16.3.5",
     "react-phone-number-input": "^3.4.14",