fix: apply default spawn name when user presses Enter without typing (#1605)

promptSpawnName() used `placeholder` (visual hint only) without `defaultValue`,
so pressing Enter returned an empty string instead of applying the placeholder.
Now generates a unique default like `spawn-a3f2` with a random suffix to avoid
Fly.io global name collisions.

Co-authored-by: Claude <claude@anthropic.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@openrouter/spawn",
-  "version": "0.5.19",
+  "version": "0.5.20",
   "type": "module",
   "bin": {
     "spawn": "cli.js"

cli/src/commands.ts

@@ -459,9 +459,12 @@ async function selectCloud(manifest: Manifest, cloudList: string[], hintOverride
 // Any string is allowed (spaces, uppercase, etc.) — the shell scripts
 // derive a kebab-case slug for the actual cloud resource name.
 async function promptSpawnName(): Promise<string | undefined> {
+  const suffix = Math.random().toString(36).slice(2, 6);
+  const defaultName = `spawn-${suffix}`;
   const spawnName = await p.text({
     message: "Name your spawn",
-    placeholder: "My Spawn",
+    placeholder: defaultName,
+    defaultValue: defaultName,
     validate: (value) => {
       if (!value) return undefined;
       if (value.length > 128) {