Add docs for Cancelling invocation

[hiroTamada]

Description

Please provide an explanation of the changes you've made:

This PR adds documentation for stopping/cancelling invocations via the API. Previously, the docs stated that stopping invocations via API was "coming very soon". This update provides clear examples showing how to stop an invocation by setting its status to failed, with code examples in both TypeScript/JavaScript and Python.

Implementation Checklist

• If updating our sample apps, update the info in our Quickstart
• If updating our CLI, update the info in our CLI

Testing

• mintlify dev works (see installation here)

Docs

• Link to a PR in our docs repo documenting your change (if applicable)
  This PR is already in the docs repo

Visual Proof

Please provide a screenshot or video demonstrating that your changes work locally:

The updated documentation shows:

• Clear explanation that invocations can be stopped by setting status to failed
• TypeScript/JavaScript example with proper SDK usage
• Python example with proper SDK usage
• Both examples include error output to indicate cancellation

Related Issue

Fixes [Github issue link]

[If this corresponds to a fix from another Kernel OSS repo, include this:]

No specific issue linked - this was a documentation improvement based on the Go client example provided

Additional Notes

• Verified the SDK schemas are correct by installing both @onkernel/sdk (npm) and kernel (pip) packages and testing the method signatures
• The examples follow the same pattern as other API documentation in the codebase
• Maintained consistency with the existing documentation style using <CodeGroup> for multi-language examples

---

TL;DR

Added documentation for cancelling an API invocation by setting its status to failed.

Why we made these changes

The previous documentation for this feature was a "coming soon" placeholder. This PR adds the official guide and code examples so users can cancel in-progress invocations via the API.

What changed?

• Updated apps/invoke.mdx to replace the placeholder with a guide on cancelling invocations.
• Added code examples in a <CodeGroup> for both TypeScript/JavaScript and Python, demonstrating how to patch the invocation's status.

^{Description generated by Mesa. Update settings}

[mesa-dot-dev]

Performed full review of 206aaab...48aa566

Analysis

1. No architectural issues identified - this appears to be a straightforward documentation update that follows established patterns in the codebase.

Tip

⚡ Quick Actions

This review was generated by Mesa.

Actions:

• Configure your agents

Slash Commands:

• /review - Request a full code review
• /review latest - Review only changes since the last review
• /describe - Generate PR description. This will update the PR body or issue comment depending on your configuration
• /help - Get help with Mesa commands and configuration options

^{1 files reviewed | 0 comments | Review on Mesa | Edit Reviewer Settings}

[masnwilliams]

lgtm