Add graph visualization exports (Milestone 7)

- Add interactive HTML export with D3.js force-directed graph
- Add SVG export with simple force-directed layout
- Add Mermaid diagram export for documentation
- Support subgraph export from root node with depth
- Add node filtering by kind and tags
- Add light/dark theme support
- Add CLI commands: export, viz
- Add MCP tool: memory_export

src/cli/index.ts

@@ -19,6 +19,7 @@ import { contextCommand, contextHookCommand } from './commands/context';
 import { indexCommand } from './commands/index-cmd';
 import { journalCommand, journalAliasCommand, quickCaptureCommand } from './commands/journal';
 import { ingestCommand, clipCommand } from './commands/ingest';
+import { exportCommand, vizCommand } from './commands/export';
 import { closeDb } from '../core/db';
 
 const program = new Command();
@@ -53,6 +54,8 @@ program.addCommand(journalAliasCommand);
 program.addCommand(quickCaptureCommand);
 program.addCommand(ingestCommand);
 program.addCommand(clipCommand);
+program.addCommand(exportCommand);
+program.addCommand(vizCommand);
 
 program.hook('postAction', () => {
   closeDb();