feat(memory): add registerMemoryCommand for mosaic memory CLI surface

Adds mosaic memory CLI with four subcommands: search, stats,
insights list, and preferences list. Commands accept --db flag
(or MEMORY_DB_URL/DATABASE_URL env) to connect to pgvector or
keyword adapter. Smoke tests verify command wiring without DB.

Task: CU-05-04

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

packages/mosaic/package.json

@@ -31,6 +31,7 @@
     "@mosaicstack/config": "workspace:*",
     "@mosaicstack/forge": "workspace:*",
     "@mosaicstack/macp": "workspace:*",
+    "@mosaicstack/memory": "workspace:*",
     "@mosaicstack/prdy": "workspace:*",
     "@mosaicstack/quality-rails": "workspace:*",
     "@mosaicstack/queue": "workspace:*",

packages/mosaic/src/cli.ts

@@ -3,6 +3,7 @@
 import { createRequire } from 'module';
 import { Command } from 'commander';
 import { registerBrainCommand } from '@mosaicstack/brain';
+import { registerMemoryCommand } from '@mosaicstack/memory';
 import { registerQualityRails } from '@mosaicstack/quality-rails';
 import { registerQueueCommand } from '@mosaicstack/queue';
 import { registerAgentCommand } from './commands/agent.js';
@@ -343,6 +344,10 @@ registerBrainCommand(program);
 
 registerQualityRails(program);
 
+// ─── memory ──────────────────────────────────────────────────────────────
+
+registerMemoryCommand(program);
+
 // ─── queue ───────────────────────────────────────────────────────────────
 
 registerQueueCommand(program);