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>

pnpm-lock.yaml

@@ -441,6 +441,9 @@ importers:
       '@mosaicstack/types':
         specifier: workspace:*
         version: link:../types
+      commander:
+        specifier: ^13.0.0
+        version: 13.1.0
       drizzle-orm:
         specifier: ^0.45.1
         version: 0.45.1(@electric-sql/pglite@0.2.17)(@opentelemetry/api@1.9.0)(@types/better-sqlite3@7.6.13)(@types/pg@8.15.6)(better-sqlite3@12.8.0)(kysely@0.28.11)(postgres@3.4.8)
@@ -469,6 +472,9 @@ importers:
       '@mosaicstack/macp':
         specifier: workspace:*
         version: link:../macp
+      '@mosaicstack/memory':
+        specifier: workspace:*
+        version: link:../memory
       '@mosaicstack/prdy':
         specifier: workspace:*
         version: link:../prdy