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/app/api/users/search/route.ts

@@ -0,0 +1,29 @@
+import { NextRequest, NextResponse } from 'next/server'
+import prisma from '@/lib/prisma'
+import { auth } from '@/auth'
+
+export async function GET(request: NextRequest) {
+  const session = await auth()
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+  }
+
+  const q = request.nextUrl.searchParams.get('q') || ''
+  if (q.length < 2) {
+    return NextResponse.json({ users: [] })
+  }
+
+  const users = await prisma.user.findMany({
+    where: {
+      id: { not: session.user.id },
+      OR: [
+        { email: { contains: q, mode: 'insensitive' } },
+        { name: { contains: q, mode: 'insensitive' } },
+      ],
+    },
+    select: { id: true, name: true, email: true, image: true },
+    take: 8,
+  })
+
+  return NextResponse.json({ users })
+}