feat: editor improvements and architectural grid prototype

Multiple feature additions and improvements across the application:

- NextGen Editor: drag handles, smart paste, block actions
- Structured views: Kanban and table layouts for notes
- Architectural Grid: new brainstorming/agent interface prototype
- Flashcards: SM-2 revision algorithm with AI generation
- MCP server: robustness improvements
- Graph/PDF chat: fix click propagation and copy behavior
- Various UI/UX enhancements and bug fixes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/next.config.ts

@@ -63,7 +63,7 @@ const nextConfig: NextConfig = {
       },
       {
         source: '/reminders',
-        destination: '/?reminders=1',
+        destination: '/home?reminders=1',
         permanent: false,
       },
     ]