Add multi-graph support (Milestone 9)

- Graph manager: create, list, delete, use graphs
- Automatic project detection via .cortex.json or git remote
- Graph switching in db.ts connection manager
- Cross-graph search with --all-graphs flag
- CLI: graphs, use, init commands
- MCP tools: memory_graphs, memory_use_graph, memory_create_graph, memory_delete_graph
- Database migration from .memory to ~/.cortex/graphs

src/cli/index.ts

@@ -22,7 +22,9 @@ import { ingestCommand, clipCommand } from './commands/ingest';
 import { exportCommand, vizCommand } from './commands/export';
 import { importCommand } from './commands/import';
 import { backupCommand, restoreDbCommand, listBackupsCommand } from './commands/backup-cmd';
+import { graphsCommand, useCommand, initCommand } from './commands/graphs';
 import { closeDb } from '../core/db';
+import { migrateOldDatabase } from '../core/db';
 
 const program = new Command();
 
@@ -62,6 +64,12 @@ program.addCommand(importCommand);
 program.addCommand(backupCommand);
 program.addCommand(restoreDbCommand);
 program.addCommand(listBackupsCommand);
+program.addCommand(graphsCommand);
+program.addCommand(useCommand);
+program.addCommand(initCommand);
+
+// Check for old database migration
+migrateOldDatabase();
 
 program.hook('postAction', () => {
   closeDb();