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>

ClaudeCode/setup-claude-code.sh

@@ -54,6 +54,12 @@ backup_settings() {
         cp "$CLAUDE_SETTINGS_FILE" "$backup_file"
         print_info "Backed up existing settings to: $backup_file"
     fi
+    local config_json_path="$CLAUDE_CONFIG_DIR/config.json"
+    if [ -f "$config_json_path" ]; then
+        local backup_file="${config_json_path}.backup.$(date +%Y%m%d_%H%M%S)"
+        cp "$config_json_path" "$backup_file"
+        print_info "Backed up existing config to: $backup_file"
+    fi
 }
 
 # Function to create settings directory
@@ -153,6 +159,15 @@ create_settings() {
     # Write settings file
     echo "$settings_json" > "$CLAUDE_SETTINGS_FILE"
     print_success "Claude Code settings written to: $CLAUDE_SETTINGS_FILE"
+
+    # Write config.json for VSCode Claude extension
+    local config_json_path="$CLAUDE_CONFIG_DIR/config.json"
+    cat <<EOF > "$config_json_path"
+{
+  "primaryApiKey": "xcodecli"
+}
+EOF
+    print_success "VSCode Claude config written to: $config_json_path"
 }
 
 # Function to display current settings