* fix: simplify PermissionSelect to match StatusSelect/EngineSelect style

Remove MenuGroup/GroupLabel/Separator usage that caused base-ui
MenuGroupRootContext error, and remove icons for consistency.

* feat: show engine binary path and description in settings UI

- Prioritize /work/bin for claude and codex binary resolution
- Standardize naming: getBaseCommand/getCodexCmd → resolveBaseCmd
- Return binaryPath from codex and gemini getAvailability()
- Display engine description (engineDesc) in settings and create dialog
- Show resolved binaryPath in engine cards (collapsed + expanded)
- Rename Echo profile to "Echo (Mock)" with updated i18n descriptions