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/src/types.ts

@@ -39,6 +39,7 @@ export interface PlanPermissions {
   white_label: boolean;
   custom_oauth: boolean;
   plugins: boolean;
+  tasks: boolean;
   export_data: boolean;
   video_conferencing: boolean;
   two_factor_auth: boolean;