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

@@ -29,6 +29,7 @@
   "dependencies": {
     "@mosaicstack/config": "workspace:*",
     "@mosaicstack/forge": "workspace:*",
+    "@mosaicstack/log": "workspace:*",
     "@mosaicstack/macp": "workspace:*",
     "@mosaicstack/prdy": "workspace:*",
     "@mosaicstack/quality-rails": "workspace:*",

packages/mosaic/src/cli.ts

@@ -2,6 +2,7 @@
 
 import { createRequire } from 'module';
 import { Command } from 'commander';
+import { registerLogCommand } from '@mosaicstack/log';
 import { registerQualityRails } from '@mosaicstack/quality-rails';
 import { registerAgentCommand } from './commands/agent.js';
 import { registerMissionCommand } from './commands/mission.js';
@@ -318,6 +319,10 @@ registerMissionCommand(program);
 
 registerQualityRails(program);
 
+// ─── log ─────────────────────────────────────────────────────────────────
+
+registerLogCommand(program);
+
 // ─── update ─────────────────────────────────────────────────────────────
 
 program