feat(macp): add registerMacpCommand for mosaic macp CLI surface

Adds mosaic macp tasks list|submit|gate|events tail subcommands to
@mosaicstack/macp, wires registerMacpCommand into the root mosaic CLI,
and ships a smoke test asserting command structure without touching disk
or starting an event emitter. Ref CU-05-08.

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

pnpm-lock.yaml

@@ -416,6 +416,10 @@ importers:
         version: 2.1.9(@types/node@24.12.0)(jsdom@29.0.0(@noble/hashes@2.0.1))(lightningcss@1.31.1)
 
   packages/macp:
+    dependencies:
+      commander:
+        specifier: ^13.0.0
+        version: 13.1.0
     devDependencies:
       '@types/node':
         specifier: ^22.0.0