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/useGeminiStream.ts

@@ -19,6 +19,7 @@ import type {
 } from '@qwen-code/qwen-code-core';
 import {
   GeminiEventType as ServerGeminiEventType,
+  createDebugLogger,
   getErrorMessage,
   isNodeError,
   MessageSenderType,
@@ -65,6 +66,8 @@ import { useSessionStats } from '../contexts/SessionContext.js';
 import { useKeypress } from './useKeypress.js';
 import type { LoadedSettings } from '../../config/settings.js';
 
+const debugLogger = createDebugLogger('GEMINI_STREAM');
+
 enum StreamProcessingStatus {
   Completed,
   UserCancelled,
@@ -990,7 +993,7 @@ export const useGeminiStream = (
           if (processingStatus === StreamProcessingStatus.UserCancelled) {
             // Restore original model if it was temporarily overridden
             restoreOriginalModel().catch((error) => {
-              console.error('Failed to restore original model:', error);
+              debugLogger.error('Failed to restore original model:', error);
             });
             isSubmittingQueryRef.current = false;
             return;
@@ -1007,12 +1010,12 @@ export const useGeminiStream = (
 
           // Restore original model if it was temporarily overridden
           restoreOriginalModel().catch((error) => {
-            console.error('Failed to restore original model:', error);
+            debugLogger.error('Failed to restore original model:', error);
           });
         } catch (error: unknown) {
           // Restore original model if it was temporarily overridden
           restoreOriginalModel().catch((error) => {
-            console.error('Failed to restore original model:', error);
+            debugLogger.error('Failed to restore original model:', error);
           });
 
           if (error instanceof UnauthorizedError) {
@@ -1082,7 +1085,7 @@ export const useGeminiStream = (
                 ToolConfirmationOutcome.ProceedOnce,
               );
             } catch (error) {
-              console.error(
+              debugLogger.error(
                 `Failed to auto-approve tool call ${call.request.callId}:`,
                 error,
               );