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/lib/ai/tools/pptx.tool.ts

@@ -60,7 +60,7 @@ const PALETTES: Record<string, Theme> = {
   coastal_coral:       { primary: '005f73', secondary: '0a9396', accent: 'ee9b00', light: 'e9f5f5', bg: 'ffffff' },
   vibrant_orange_mint: { primary: 'e05c00', secondary: '2ec4b6', accent: 'ff9f1c', light: 'edfaf9', bg: 'ffffff' },
   platinum_white_gold: { primary: '0a0a0a', secondary: '404040', accent: 'c9a84c', light: 'f5f5f0', bg: 'ffffff' },
-  architectural_mono:  { primary: '1C1C1C', secondary: '75B2D6', accent: 'D4A373', light: 'EDE9DF', bg: 'F2F0E9' },
+  architectural_mono:  { primary: '1C1C1C', secondary: 'A47148', accent: 'D4A373', light: 'EDE9DF', bg: 'F2F0E9' },
   minimal_silk:        { primary: '212529', secondary: '6c757d', accent: 'dee2e6', light: 'f8f9fa', bg: 'ffffff' },
 }