feat: final schema pass — sync 9 schema changes from main repo

- Rename nodes.content → nodes.notes across all services, tools, API routes, and UI
- Add dimensions.icon column support (GET/POST routes, types)
- Add nodes.event_date column (create/update flows, types)
- Drop nodes.type and nodes.is_pinned references
- Drop edges.user_feedback references
- Drop chat_memory_state table (replaced with DROP IF EXISTS in migration)
- Update schema guide files (system/schema.md)
- Add runtime migration block in sqlite-client.ts for existing databases
- Fix MCP tool schemas (external API keeps 'content' param, maps to 'notes' internally)
- Update standalone MCP server (nodeService.js, sqlite-client.js, index.js)
- Update HTTP MCP server (server.js, stdio-server.js)
- Update all extraction tools (paper, website, youtube)
- Update all UI components (FocusPanel, ThreePanelLayout, GridView, ListView, FolderViewOverlay)
- TypeScript: 0 errors

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/views/GridView.tsx

@@ -104,7 +104,7 @@ export default function GridView({ nodes, onNodeClick }: GridViewProps) {
               </div>
 
               {/* Description or Content Preview */}
-              {(node.description || node.content) && (
+              {(node.description || node.notes) && (
                 <div style={{
                   flex: 1,
                   fontSize: '11px',
@@ -116,7 +116,7 @@ export default function GridView({ nodes, onNodeClick }: GridViewProps) {
                   WebkitBoxOrient: 'vertical',
                   marginBottom: '10px'
                 }}>
-                  {node.description || truncateContent(node.content)}
+                  {node.description || truncateContent(node.notes)}
                 </div>
               )}
 

src/components/views/ListView.tsx

@@ -105,7 +105,7 @@ export default function ListView({ nodes, onNodeClick }: ListViewProps) {
               </div>
 
               {/* Description or Content Preview */}
-              {(node.description || node.content) && (
+              {(node.description || node.notes) && (
                 <div style={{
                   fontSize: '12px',
                   color: '#666',
@@ -116,7 +116,7 @@ export default function ListView({ nodes, onNodeClick }: ListViewProps) {
                   WebkitBoxOrient: 'vertical',
                   overflow: 'hidden'
                 }}>
-                  {node.description || truncateContent(node.content)}
+                  {node.description || truncateContent(node.notes)}
                 </div>
               )}