- Migrated global service tier settings to a per-model-family architecture (OpenAI, Anthropic, Google).
- Implemented `ServiceTierByFamily` mapping to allow independent configuration and resolution per provider.
- Added automatic migration logic for legacy service tier and fast-mode application settings.
- Updated telemetry, session management, and task execution to support provider-specific tier resolution.
Adds a fastModeScope setting (both|openai|claude, default both). setFastMode(true)
derives the service tier from it (both->priority, openai->openai-only,
claude->claude-only) instead of hardcoding unscoped priority; the off path and
the already-on no-op are unchanged. /fast status now reports the active scope.
Default both preserves existing behavior.
can1357