Before optimization:
- useSettings.ts: 516 lines (single monolithic hook)
After optimization:
- useSettingsForm.ts: 158 lines (form state management)
- useDirectorySettings.ts: 297 lines (directory management)
- useSettingsMetadata.ts: 95 lines (metadata management)
- useSettings.ts: 215 lines (composition layer)
- Total: 765 lines (+249 lines, but with clear separation of concerns)
Benefits:
✅ Single Responsibility Principle: each hook focuses on one domain
✅ Testability: independent hooks are easier to unit test
✅ Reusability: specialized hooks can be reused in other components
✅ Maintainability: reduced cognitive load per file
✅ Zero breaking changes: SettingsDialog auto-adapted to new interface
Technical details:
- useSettingsForm: pure form state + language sync
- useDirectorySettings: directory selection/reset + default value computation
- useSettingsMetadata: config path + portable mode + restart flag
- useSettings: composition layer + save logic + reset logic
