feat(cli): migrate console calls to debugLogger and stdioHelpers (M3 Phase 7-9)

Route CLI console.* calls to structured logging:
- Debug/internal diagnostics → debugLogger (logfile)
- User-facing output → writeStdoutLine/writeStderrLine/clearScreen (stdioHelpers)
- Add stdioHelpers.ts with writeStdoutLine, writeStderrLine, clearScreen
- Migrate pre-session files (gemini.tsx, sandbox.ts, config.ts) to stdioHelpers
- Migrate extension/MCP commands to stdioHelpers
- Migrate non-interactive session/control to debugLogger
- Migrate UI hooks and components to debugLogger

packages/cli/src/ui/hooks/useSelectionList.ts

@@ -5,6 +5,7 @@
  */
 
 import { useReducer, useRef, useEffect } from 'react';
+import { createDebugLogger } from '@qwen-code/qwen-code-core';
 import { useKeypress } from './useKeypress.js';
 
 export interface SelectionListItem<T> {
@@ -22,6 +23,8 @@ export interface UseSelectionListOptions<T> {
   showNumbers?: boolean;
 }
 
+const debugLogger = createDebugLogger('SELECTION_LIST');
+
 export interface UseSelectionListResult {
   activeIndex: number;
   setActiveIndex: (index: number) => void;
@@ -203,7 +206,7 @@ function selectionListReducer<T>(
 
     default: {
       const exhaustiveCheck: never = action;
-      console.error(`Unknown selection list action: ${exhaustiveCheck}`);
+      debugLogger.error(`Unknown selection list action: ${exhaustiveCheck}`);
       return state;
     }
   }