Data-driven presets (smart/deep/fast/large/precise) bundling model + reasoning effort + max turns (+ optional tool filter), resolved through the registry. --mode seeds only unset exec options so explicit --model/-r/--max-turns still win; /mode lists/switches in the TUI. Build/vet/test green.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>