Fix Cowork model selection and Windows CLI packaging (#1129)

Cherry-picked from upstream PR #1129 + local improvements:
- dedupe inline remove-model handler -> use handleRemoveModel
- add .next-cli-build/ and cli/.build-home/ to .gitignore

.gitignore

@@ -15,7 +15,9 @@
 
 # next.js
 /.next/
+/.next-cli-build/
 /out/
+cli/.build-home/
 product
 # production
 /build