- Add i18n.SetDefault() in CLI service for global i18n.T() access
- Replace explicit cmd.php.qa.* keys with grammar-based composition
- Use i18n.Label(), i18n.ProgressSubject() for structured messages
- Use i18n.done.*, i18n.fail.*, i18n.count.* magic namespaces
- Simplify GetIssueMessage() to use grammar patterns
This reduces translation key explosion by composing messages from
grammar primitives rather than defining explicit keys for every phrase.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>