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/hierarchical-notebook-selector.tsx

@@ -111,7 +111,7 @@ export function HierarchicalNotebookSelector({
                   if (!searchQuery) setIsOpen(false)
                 }}
                 className={`flex items-center gap-2.5 px-2 py-1.5 rounded-lg cursor-pointer transition-all group
-                  ${isSelected ? 'bg-blueprint/10 text-blueprint font-bold dark:bg-blueprint/10' : 'hover:bg-muted dark:hover:bg-white/5 text-ink'}`}
+                  ${isSelected ? 'bg-memento-blue/15 text-memento-blue font-bold dark:bg-memento-blue/20' : 'hover:bg-muted dark:hover:bg-white/5 text-ink'}`}
               >
                 <div className="w-4 flex items-center justify-center">
                   {hasChildren ? (
@@ -124,7 +124,7 @@ export function HierarchicalNotebookSelector({
                   ) : null}
                 </div>
 
-                <div className={`p-1 rounded ${isSelected ? 'bg-blueprint/20 dark:bg-blueprint/20' : 'bg-muted/50 dark:bg-white/5 group-hover:bg-white/40'}`}>
+                <div className={`p-1 rounded ${isSelected ? 'bg-memento-blue/25 dark:bg-memento-blue/30' : 'bg-muted/50 dark:bg-white/5 group-hover:bg-white/40'}`}>
                   {isExpanded && hasChildren ? <FolderOpen size={13} /> : <Folder size={13} />}
                 </div>
 
@@ -157,9 +157,9 @@ export function HierarchicalNotebookSelector({
       <div
         ref={triggerRef}
         onClick={() => setIsOpen(prev => !prev)}
-        className={`w-full bg-card dark:bg-white/5 border border-border/80 rounded-xl outline-none focus:ring-4 ring-blueprint/5 focus:border-blueprint/40 transition-all cursor-pointer text-ink flex items-center gap-3 ${size === 'sm' ? 'px-3 py-2 text-xs' : 'px-4 py-3 text-sm'}`}
+        className={`w-full bg-card dark:bg-white/5 border border-border/80 rounded-xl outline-none focus:ring-4 ring-memento-blue/10 focus:border-memento-blue/40 transition-all cursor-pointer text-ink flex items-center gap-3 ${size === 'sm' ? 'px-3 py-2 text-xs' : 'px-4 py-3 text-sm'}`}
       >
-        <Folder size={size === 'sm' ? 14 : 16} className="text-blueprint/60 shrink-0" />
+        <Folder size={size === 'sm' ? 14 : 16} className="text-memento-blue/70 shrink-0" />
         <div className="flex-1 flex items-center gap-1 min-w-0">
           {path.length > 0 ? (
             <div className="flex items-center gap-1.5 truncate">
@@ -201,7 +201,7 @@ export function HierarchicalNotebookSelector({
                     value={searchQuery}
                     onChange={(e) => setSearchQuery(e.target.value)}
                     placeholder={placeholder}
-                    className="w-full bg-card border border-border rounded-lg pl-9 pr-4 py-2 text-xs outline-none focus:border-blueprint transition-colors"
+                    className="w-full bg-card border border-border rounded-lg pl-9 pr-4 py-2 text-xs outline-none focus:border-memento-blue transition-colors"
                   />
                 </div>
               </div>
@@ -216,7 +216,7 @@ export function HierarchicalNotebookSelector({
                 </span>
                 <button
                   onClick={() => setIsOpen(false)}
-                  className="text-[10px] font-bold text-blueprint hover:underline"
+                  className="text-[10px] font-bold text-memento-blue hover:underline"
                 >
                   Close
                 </button>