feat(forge): add registerForgeCommand for mosaic forge CLI surface

Adds mosaic forge run|status|resume|personas list subcommands to
@mosaicstack/forge, wires registerForgeCommand into the root mosaic CLI,
and ships a smoke test asserting command structure. Ref CU-05-01
cli-unification-20260404.

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

packages/mosaic/src/cli.ts

@@ -3,6 +3,7 @@
 import { createRequire } from 'module';
 import { Command } from 'commander';
 import { registerBrainCommand } from '@mosaicstack/brain';
+import { registerForgeCommand } from '@mosaicstack/forge';
 import { registerQualityRails } from '@mosaicstack/quality-rails';
 import { registerQueueCommand } from '@mosaicstack/queue';
 import { registerAgentCommand } from './commands/agent.js';
@@ -344,6 +345,10 @@ registerMissionCommand(program);
 
 registerBrainCommand(program);
 
+// ─── forge ───────────────────────────────────────────────────────────────
+
+registerForgeCommand(program);
+
 // ─── quality-rails ──────────────────────────────────────────────────────
 
 registerQualityRails(program);