Closes#28 (first half; the DataClassification and loopback gateway
stand-ins go with RC.6).
- Default QQQ is 4.1.0-RC.5.
- BudgetAlerts calls QAlerts.raise(AlertSignal...) directly instead of
binding by reflection.
- The producer declares assistant.budget.warning, .downgraded and .stopped
as QAlertTypeMetaData (assistant.admin, subject assistant_budget).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>