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/components/note-editor/note-content-area.tsx

@@ -107,6 +107,7 @@ export function NoteContentArea() {
           className="min-h-[280px]"
           onImageUpload={uploadImageFile}
           noteId={note.id}
+          noteTitle={state.title || note.title}
           sourceUrl={note.sourceUrl}
         />
       </div>
@@ -122,6 +123,7 @@ export function NoteContentArea() {
         className="min-h-[200px]"
         onImageUpload={uploadImageFile}
         noteId={note.id}
+        noteTitle={state.title || note.title}
         sourceUrl={note.sourceUrl}
       />
       <GhostTags