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.sh

@@ -42,6 +42,12 @@ backup_settings() {
         cp "$GEMINI_ENV_FILE" "$backup_file"
         print_info "Backed up existing settings to: $backup_file"
     fi
+    local settings_json_path="$GEMINI_CONFIG_DIR/settings.json"
+    if [ -f "$settings_json_path" ]; then
+        local backup_file="${settings_json_path}.backup.$(date +%Y%m%d_%H%M%S)"
+        cp "$settings_json_path" "$backup_file"
+        print_info "Backed up existing settings to: $backup_file"
+    fi
 }
 
 # Function to create settings directory
@@ -122,8 +128,25 @@ create_settings_file() {
     cat <<EOF > "$GEMINI_ENV_FILE"
 GOOGLE_GEMINI_BASE_URL="$base_url"
 GEMINI_API_KEY="$api_key"
+GEMINI_MODEL="gemini-3-pro-preview"
 EOF
     print_success "Gemini CLI settings written to: $GEMINI_ENV_FILE"
+
+    # Write to settings.json
+    local settings_json_path="$GEMINI_CONFIG_DIR/settings.json"
+    cat <<EOF > "$settings_json_path"
+{
+  "general": {
+    "previewFeatures": true
+  },
+  "security": {
+    "auth": {
+      "selectedType": "gemini-api-key"
+    }
+  }
+}
+EOF
+    print_success "Gemini CLI settings written to: $settings_json_path"
 }
 
 # Function to display current settings