[sandbox-cli] Add detached command controls

[erulkey]

The SDK can start a command and return its ID while it keeps running. The CLI currently waits for every sandbox exec command, so terminal users cannot return later to read logs or stop the process. This adds sandbox exec --detach and sandbox commands get|logs|wait|kill for the current running session.

command_id=$(sandbox exec --detach my-sandbox -- npm run dev)
sandbox commands logs my-sandbox "$command_id"
sandbox commands kill my-sandbox "$command_id"

Command lookup requires a running session, so inspecting an ID cannot resume a stopped sandbox into a new session. sandbox run keeps its existing create-and-wait behavior. The generated help and skills/sandbox/SKILL.md include the new commands.

Verified with the built CLI: typecheck and build passed; all 226 CLI tests passed. In a playground sandbox, separate CLI processes started a detached command, streamed its output, waited for exit 0, and killed another command with exit 137 while the sandbox remained running. The test sandbox was removed.

Companion docs: vercel/front#91668. Publish the CLI before merging its new public examples.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
sandbox	Ready	Preview, v0	Oct 16, 2026 9:51pm UTC
sandbox-cli	Ready	Preview, v0	Oct 16, 2026 9:51pm UTC
sandbox-sdk-ai-example	Ready	Preview, v0	Oct 16, 2026 9:51pm UTC
workflow-code-runner	Ready	Preview, v0	Oct 16, 2026 9:51pm UTC

[vercel]

Additional Suggestion:

The connect command exposes a --detach flag that always errors because connect always runs interactively, and --detach cannot be combined with --interactive.