feat: add reasoning effort support for Codex models

- Add ReasoningEffortSelector component for UI selection
- Integrate reasoning effort in feature creation/editing dialogs
- Add reasoning effort support to phase model selector
- Update agent service and board actions to handle reasoning effort
- Add reasoning effort fields to feature and settings types
- Update model selector and agent info panel with reasoning effort display
- Enhance agent context parser for reasoning effort processing

Reasoning effort allows fine-tuned control over Codex model reasoning
capabilities, providing options from 'none' to 'xhigh' for different
task complexity requirements.

apps/ui/src/components/views/board-view/shared/index.ts

@@ -1,6 +1,7 @@
 export * from './model-constants';
 export * from './model-selector';
 export * from './thinking-level-selector';
+export * from './reasoning-effort-selector';
 export * from './profile-quick-select';
 export * from './profile-select';
 export * from './testing-tab-content';