fix(migrate): move pnpm settings to workspace config

Author: fengmk2

packages/cli/snap-tests-global/migration-upgrade-stale-local-pnpm/snap.txt

@@ -4,7 +4,7 @@
 • Node <semver>  pnpm <semver>
 • Package manager settings configured
 
-> cat package.json # stale wrapper deps and plain vite-plus range should be repaired
+> cat package.json # stale wrapper deps and plain vite-plus range should be repaired; empty pnpm field should be removed
 {
   "name": "migration-upgrade-stale-local-pnpm",
   "devDependencies": {
@@ -17,11 +17,10 @@
       "version": "<semver>",
       "onFail": "download"
     }
-  },
-  "pnpm": {}
+  }
 }
 
-> cat pnpm-workspace.yaml # empty pnpm field must not hide workspace overrides
+> cat pnpm-workspace.yaml # pnpm settings should be consolidated here
 overrides:
   vite: 'catalog:'
 peerDependencyRules:

packages/cli/snap-tests-global/migration-upgrade-stale-local-pnpm/steps.json

@@ -3,7 +3,7 @@
   "commands": [
     { "command": "node setup-local.mjs", "ignoreOutput": true },
     "vp migrate --no-interactive # newer global CLI must bypass the installed stale local CLI",
-    "cat package.json # stale wrapper deps and plain vite-plus range should be repaired",
-    "cat pnpm-workspace.yaml # empty pnpm field must not hide workspace overrides"
+    "cat package.json # stale wrapper deps and plain vite-plus range should be repaired; empty pnpm field should be removed",
+    "cat pnpm-workspace.yaml # pnpm settings should be consolidated here"
   ]
 }