fix(macp): point exports.default at dist/index.js + add CLI smoke test (CU-05-09, CU-05-10)

macp package.json had a pre-existing exports map with default: './src/index.ts'
which broke any consumer that loaded the compiled mosaic CLI via node (mosaic
--help, mosaic <cmd> --help). Every other workspace package points at
./dist/index.js — align macp with the rest.

Adds packages/mosaic/src/cli-smoke.spec.ts — the CU-05-10 integration smoke
test that asserts every register<Name>Command from the eight sub-packages
(auth, brain, forge, log, macp, memory, queue, storage) plus config attaches a
top-level command and that its help output renders without throwing. Running
this locally after the macp fix confirms mosaic --help and mosaic <cmd> --help
exit 0 for all nine commands.

Part of mission cli-unification-20260404.

packages/macp/package.json

@@ -12,7 +12,7 @@
   "exports": {
     ".": {
       "types": "./dist/index.d.ts",
-      "default": "./src/index.ts"
+      "default": "./dist/index.js"
     }
   },
   "scripts": {