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

next.config.mjs

@@ -10,6 +10,7 @@ const tracingRoot = process.env.NEXT_TRACING_ROOT_MODE === "workspace"
 
 /** @type {import('next').NextConfig} */
 const nextConfig = {
+  distDir: process.env.NEXT_DIST_DIR || ".next",
   output: "standalone",
   serverExternalPackages: ["better-sqlite3", "sql.js", "node:sqlite", "bun:sqlite"],
   turbopack: {