Register hidden stub commands for official GitHub extensions (gh-aw,
gh-stack) that offer to install the extension when invoked. This
replaces the error-string-matching approach from the original PR with
proper cobra commands that:
- Avoid false-positive matches on flag values or post-'--' args
- Eliminate conflicting cobra 'Did you mean?' suggestions
- Properly propagate prompt/install errors for correct exit codes
- Are hidden from help output and shell completions
- Use GroupID "extension" so checkValidExtension allows installing over them
- Are registered after extensions and aliases so both take priority
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
When a user runs an unknown command that matches a known official
extension (e.g. `gh stack` or `gh aw`), show an install suggestion.
In interactive TTY sessions, prompt the user to install it on the spot.
The official extension registry is hard-coded in pkg/extensions/.
Current entries are github/gh-aw and github/gh-stack. Teams can add
their extensions via PR. Install suggestions use an explicit github.com
host prefix for GHES compatibility.
Refs github/cli#220
Co-Authored-By: Copilot <223556219+Copilot@users.noreply.github.com>
