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/agents/agent-card.tsx

@@ -18,6 +18,7 @@ import {
   Pencil,
   Activity,
   Presentation,
+  ListChecks,
 } from 'lucide-react'
 import { toast } from 'sonner'
 import { useLanguage } from '@/lib/i18n'
@@ -51,6 +52,7 @@ const typeConfig: Record<string, { icon: typeof Globe }> = {
   custom: { icon: Settings },
   'slide-generator': { icon: Presentation },
   'excalidraw-generator': { icon: Pencil },
+  'task-extractor': { icon: ListChecks },
 }
 
 const frequencyKeys: Record<string, string> = {