Make cratis update installation-aware with Homebrew update+upgrade and unified post-command update hints

[Copilot]

• Inspect current branch state and verify whether brew update is present in code
• If missing, add/restore brew update before Homebrew upgrade in self-update flow
• Run focused tests for update behavior
• Run security scan and finalize
• Commit/push and reply to PR comment with commit hash

[einari]

@copilot Great. Since cratis is not part of the default Homebrew tap, we need to run brew update and then the upgrade.

[Copilot]

@copilot Great. Since cratis is not part of the default Homebrew tap, we need to run brew update and then the upgrade.

Implemented in db70895. Homebrew updates now run brew update first and then brew upgrade cratis in the self-update flow, with focused specs added for the pre-update Homebrew command behavior.

[einari]

@copilot Weird, you said brew update as added - but its not in the code

[Copilot]

@copilot Weird, you said brew update as added - but its not in the code

It is in the branch at db70895: Source/Cli/CliUpdate.cs adds CreatePreUpdateProcessStartInfo() with brew + update, and Source/Cli/Commands/Version/SelfUpdateCommand.cs calls it before CreateUpdateProcessStartInfo() (brew upgrade cratis). If you want, I can also fold it into a single Homebrew command path to make it more obvious in one place.