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>

architectural-grid1/BRAINSTORM_PROMPT.md

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+# IA Agent Coordination Prompt: Brainstorm Wave Integration
+
+## Context
+You are tasked with continuing the development of the "Architectural Grid" application. The core feature "Wave Brainstorming" has been partially implemented with a full-stack architecture (Express + React).
+
+## Current State
+- **Backend (`server.ts`)**: Implements session management, idea generation via Gemini, and expansion logic. Stores data in memory.
+- **Frontend (`BrainstormView.tsx`)**: Manages the life cycle of a brainstorm. Integrates with a Radial D3 Canvas.
+- **Visuals (`WaveCanvas.tsx`)**: Implements a radial force-directed graph with state-aware styling (dismissed/converted).
+- **Navigation**: "Brainstorm Wave" is accessible from the Sidebar. A quick entry point exists from Note Detail view.
+
+## Your Task: Sidebar & Navigation Cleanup
+1. **Source Code Review**: Read `src/components/Sidebar.tsx`, `src/App.tsx`, and `server.ts` to understand how views are toggled.
+2. **Sidebar Links**: Ensure "Brainstorm Wave", "Semantic Network", and "Temporal Forecast" are correctly grouped and labeled in the Sidebar under a "Creative & AI" section.
+3. **Agent View Sidebar**: The user specifically requested these links to be also accessible from the "Sidebar of the Agent view". Review `src/components/AgentsView.tsx` and ensure it has consistent navigation or deep links to these advanced features.
+4. **Semantic Network & Temporal Forecast**: These views are currently placeholders. Ensure the routing and sidebar active state detection work correctly for them.
+
+## Technical Requirements
+- Maintain consistency with the **Tailwind** architectural design (concrete, paper, accent tokens).
+- Use **Lucide-React** icons (`Wind` for Brainstorm, `Share2` for Semantic Network, `Clock` for Temporal).
+- Ensure transitions between views are smooth using `motion/react`.
+
+---
+*Copy and paste this into the next AI Agent session to ensure full context transfer.*