feat: 脚本创作+发布+市场体系

- 数据模型新增: title(必填), description(可选), status(draft/published)
- 新增 API: POST /scripts/:id/publish, GET /api/market (搜索+分页+runtime过滤)
- 前端首页重构: 选语言 → CodeMirror 编辑器(8种语言语法高亮) → 标题/描述 → 草稿/发布
- 新增 /market 页面: 浏览已发布脚本, 搜索+过滤+分页
- 详情页新增: 发布按钮(草稿→市场), title/description 展示
- Shell 类运行时显示 source 命令(继承环境变量)
- backend GetSourceCommand 支持 bash/zsh/sh/fish 四种 shell 格式

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/internal/config/runtime.go

@@ -35,3 +35,24 @@ func GetRuntime(name string) (RuntimeConfig, bool) {
 	rt, ok := RuntimeMap[name]
 	return rt, ok
 }
+
+func IsShellRuntime(name string) bool {
+	switch name {
+	case "bash", "zsh", "sh", "fish":
+		return true
+	}
+	return false
+}
+
+func GetSourceCommand(url, runtime string) string {
+	switch runtime {
+	case "bash", "zsh":
+		return "source <(curl " + url + ")"
+	case "sh":
+		return ". <(curl " + url + ")"
+	case "fish":
+		return "curl " + url + " | source"
+	default:
+		return ""
+	}
+}