feat: 增强三个 CLI 工具配置脚本

- Gemini CLI: 添加 GEMINI_MODEL 环境变量、settings.json 输出及备份逻辑
- Codex: 修复模型名称一致性 (gpt-5-codex)、添加 auth.json 备份逻辑
- Claude Code: 添加 VSCode 插件 config.json 配置支持
- CLAUDE.md: 重构文档，添加三个工具配置差异表

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

GeminiCLI/setup-gemini.ps1

@@ -86,6 +86,13 @@ function Backup-Settings {
         Copy-Item -Path $GeminiEnvFile -Destination $backupFile
         Write-Info "Backed up existing settings to: $backupFile"
     }
+    $settingsJsonPath = "$GeminiConfigDir\settings.json"
+    if (Test-Path $settingsJsonPath) {
+        $timestamp = Get-Date -Format "yyyyMMdd_HHmmss"
+        $backupFile = "$settingsJsonPath.backup.$timestamp"
+        Copy-Item -Path $settingsJsonPath -Destination $backupFile
+        Write-Info "Backed up existing settings to: $backupFile"
+    }
 }
 
 # Function to create settings directory
@@ -165,11 +172,27 @@ function New-Settings {
     $envContent = @"
 GOOGLE_GEMINI_BASE_URL="$BaseUrl"
 GEMINI_API_KEY="$ApiKey"
+GEMINI_MODEL="gemini-3-pro-preview"
 "@
-    
+
+    $settingsJson = @{
+        general = @{
+            previewFeatures = $true
+        }
+        security = @{
+            auth = @{
+                selectedType = "gemini-api-key"
+            }
+        }
+    }
+
     try {
         Set-Content -Path $GeminiEnvFile -Value $envContent -Encoding UTF8
         Write-Success "Gemini CLI settings written to: $GeminiEnvFile"
+
+        $settingsJsonPath = "$GeminiConfigDir\settings.json"
+        $settingsJson | ConvertTo-Json -Depth 10 | Set-Content -Path $settingsJsonPath -Encoding UTF8
+        Write-Success "Gemini CLI settings written to: $settingsJsonPath"
         return $true
     }
     catch {