feat(log): add registerLogCommand for mosaic log CLI surface

Adds mosaic log tail|search|export|level subcommands to @mosaicstack/log,
wires registerLogCommand into the root mosaic CLI, and ships a smoke test
that asserts command structure without opening the database. Ref CU-05-07.

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

packages/mosaic/package.json

@@ -30,6 +30,7 @@
     "@mosaicstack/brain": "workspace:*",
     "@mosaicstack/config": "workspace:*",
     "@mosaicstack/forge": "workspace:*",
+    "@mosaicstack/log": "workspace:*",
     "@mosaicstack/macp": "workspace:*",
     "@mosaicstack/memory": "workspace:*",
     "@mosaicstack/prdy": "workspace:*",

packages/mosaic/src/cli.ts

@@ -3,6 +3,7 @@
 import { createRequire } from 'module';
 import { Command } from 'commander';
 import { registerBrainCommand } from '@mosaicstack/brain';
+import { registerLogCommand } from '@mosaicstack/log';
 import { registerMemoryCommand } from '@mosaicstack/memory';
 import { registerQualityRails } from '@mosaicstack/quality-rails';
 import { registerQueueCommand } from '@mosaicstack/queue';
@@ -349,6 +350,10 @@ registerBrainCommand(program);
 
 registerQualityRails(program);
 
+// ─── log ─────────────────────────────────────────────────────────────────
+
+registerLogCommand(program);
+
 // ─── memory ──────────────────────────────────────────────────────────────
 
 registerMemoryCommand(program);