`app-id` deprecation warning — migrate to `client-id` in GitHub App token generation

[corygehr]

Summary

Every workflow that uses github-app checkout emits a deprecation warning on every run:

##[warning]Input 'app-id' has been deprecated with message: Use 'client-id' instead.

This isn't actionable at the workflow source level — gh-aw's schema requires app-id, and attempting to use client-id in the .md frontmatter causes a compile error (Unknown property: client-id).

Reproduction

Any workflow with a github-app checkout block:

checkout:
  - repository: ${{ github.event.inputs.trigger_ref }}
    github-app:
      app-id: ${{ secrets.MY_APP_ID }}
      private-key: ${{ secrets.MY_APP_KEY }}
      owner: my-org
      repositories: ["*"]

Compile and run → the activation job logs the deprecation warning.

Expected behavior

gh-aw should use client-id when calling the underlying action, and accept client-id (or both) in the workflow schema. No deprecation warning in job logs.

Observed behavior

• gh-aw internally passes app-id to the action, which triggers the warning
• Workflow authors cannot fix this — using client-id in the .md source fails compilation

Impact

• Deprecation warnings on every run of every workflow using GitHub App authentication
• Once the upstream action removes app-id entirely, all gh-aw workflows using GitHub App checkout will break

Environment

• gh-aw version: v0.68.3

Additional context

There's also a cosmetic token revocation fallback message in agent job logs:

gh: To use GitHub CLI in a GitHub Actions workflow, set the GH_TOKEN environment variable.
Token revoke may already be expired.

The token is successfully revoked by gh-aw's post-job cleanup (Token revoked appears later), so this is non-fatal. Might be worth suppressing the misleading intermediate message.