feat: brainstorm sessions, PDF document Q&A, embedding fixes, and UI improvements

- Add brainstorm feature with collaborative canvas, AI idea generation, live cursors, playback, and export
- Add PDF upload/extraction/ingestion pipeline with pgvector document search (RAG)
- Add document Q&A overlay with streaming chat and PDF preview
- Add note attachments UI with status polling, grid layout, and auto-scroll
- Add task extraction AI tool and agent executor improvements
- Fix NoteEmbedding missing updatedAt column, re-index 66 notes with 1536-dim embeddings
- Fix brainstorm 'Create Note' button: add success toast and redirect to created note
- Fix memory echo notification infinite polling
- Fix chat route to always include document_search tool
- Add brainstorm i18n keys across all 14 locales
- Add socket server for real-time brainstorm collaboration
- Add hierarchical notebook selector and organize notebook dialog improvements
- Add sidebar brainstorm section with session management
- Update prisma schema with brainstorm tables, attachments, and document chunks

memento-note/components/brainstorm/ghost-cursor.tsx

@@ -0,0 +1,123 @@
+'use client'
+
+import React, { useEffect, useState, useRef } from 'react'
+import { motion, AnimatePresence } from 'motion/react'
+
+interface GhostCursorProps {
+  isActive: boolean
+  containerRef: React.RefObject<HTMLDivElement | null>
+  targetId?: string | null
+}
+
+export function GhostCursor({ isActive, containerRef, targetId }: GhostCursorProps) {
+  const [position, setPosition] = useState({ x: 0, y: 0 })
+  const [visible, setVisible] = useState(false)
+  const intervalRef = useRef<NodeJS.Timeout | null>(null)
+
+  useEffect(() => {
+    if (!isActive) {
+      setVisible(false)
+      if (intervalRef.current) clearInterval(intervalRef.current)
+      return
+    }
+
+    const container = containerRef.current
+    if (!container) return
+
+    setVisible(true)
+    
+    // Initialisation sécurisée
+    const initialRect = container.getBoundingClientRect()
+    const initialCx = initialRect.width > 0 ? initialRect.width / 2 : window.innerWidth / 2
+    const initialCy = initialRect.height > 0 ? initialRect.height / 2 : window.innerHeight / 2
+
+    setPosition({
+      x: initialCx + (Math.random() - 0.5) * 200,
+      y: initialCy + (Math.random() - 0.5) * 200,
+    })
+
+    let angle = Math.random() * Math.PI * 2
+    let targetX = initialCx + Math.cos(angle) * 250
+    let targetY = initialCy + Math.sin(angle) * 250
+
+    intervalRef.current = setInterval(() => {
+      // Recalculer les dimensions à chaque tick pour s'adapter aux redimensionnements
+      const currentContainer = containerRef.current
+      if (!currentContainer) return
+
+      const containerRect = currentContainer.getBoundingClientRect()
+      const cx = containerRect.width / 2
+      const cy = containerRect.height / 2
+
+      let currentTargetX = targetX;
+      let currentTargetY = targetY;
+
+      if (targetId) {
+        const nodeElement = document.querySelector(`[data-id="${targetId}"]`);
+        if (nodeElement) {
+          const nodeRect = nodeElement.getBoundingClientRect();
+          currentTargetX = nodeRect.left - containerRect.left + nodeRect.width / 2;
+          currentTargetY = nodeRect.top - containerRect.top + nodeRect.height / 2;
+        }
+      }
+
+      setPosition(prev => {
+        const dx = currentTargetX - prev.x
+        const dy = currentTargetY - prev.y
+        const dist = Math.sqrt(dx * dx + dy * dy)
+
+        if (!targetId && dist < 20) {
+          angle = Math.random() * Math.PI * 2
+          const radius = 150 + Math.random() * 200
+          targetX = cx + Math.cos(angle) * radius
+          targetY = cy + Math.sin(angle) * radius
+        }
+
+        const speed = targetId ? 0.15 : 0.06;
+        
+        let newX = prev.x + dx * speed;
+        let newY = prev.y + dy * speed;
+        
+        // Protection Anti-NaN qui bloquait le curseur en haut à gauche
+        if (isNaN(newX)) newX = cx;
+        if (isNaN(newY)) newY = cy;
+
+        return {
+          x: newX,
+          y: newY,
+        }
+      })
+    }, 50)
+
+    return () => {
+      if (intervalRef.current) clearInterval(intervalRef.current)
+    }
+  }, [isActive, containerRef, targetId])
+
+  return (
+    <AnimatePresence>
+      {visible && (
+        <motion.div
+          initial={{ opacity: 0, scale: 0.5 }}
+          animate={{ opacity: 1, scale: 1 }}
+          exit={{ opacity: 0, scale: 0.5 }}
+          className="absolute pointer-events-none z-50"
+          style={{ transform: `translate(${position.x}px, ${position.y}px)` }}
+        >
+          <div className="relative">
+            <svg width="16" height="16" viewBox="0 0 16 16" fill="none">
+              <path d="M0 0L16 6L8 8L6 16L0 0Z" fill="#a78bfa" />
+            </svg>
+            <div className="absolute -top-1 -right-1 w-3 h-3">
+              <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-violet-400 opacity-50" />
+              <span className="relative inline-flex rounded-full h-3 w-3 bg-violet-500" />
+            </div>
+            <div className="mt-3 ml-3 px-2 py-0.5 rounded-full text-[10px] font-bold text-white whitespace-nowrap shadow-lg bg-gradient-to-r from-violet-500 to-purple-600">
+              AI ✦
+            </div>
+          </div>
+        </motion.div>
+      )}
+    </AnimatePresence>
+  )
+}