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>

apps/mcp-server-standalone/services/sqlite-client.js

@@ -50,9 +50,9 @@ function initDatabase() {
         id INTEGER PRIMARY KEY,
         title TEXT,
         description TEXT,
-        content TEXT,
+        notes TEXT,
         link TEXT,
-        type TEXT,
+        event_date TEXT,
         created_at TEXT,
         updated_at TEXT,
         metadata TEXT,
@@ -71,7 +71,7 @@ function initDatabase() {
         source TEXT,
         created_at TEXT,
         context TEXT,
-        user_feedback INTEGER,
+        
         FOREIGN KEY (from_node_id) REFERENCES nodes(id) ON DELETE CASCADE,
         FOREIGN KEY (to_node_id) REFERENCES nodes(id) ON DELETE CASCADE
       );