feat: 拆分任务类型并支持脚本语言联动

- 任务类型改为「执行脚本 / 发起 HTTP 请求 / 运行二进制程序」，脚本类型下新增语言选择（Python / Shell / Node / Lua）
- 语言联动表单：Python 才显示虚拟环境、解释器和 uv 状态；Shell/Node/Lua 隐藏这些字段并切换脚本标签、占位符和调用预览
- 切换语言时自动设置解释器与默认脚本，Shell 通过 cmd.exe /C 执行批处理，Node/Lua 使用对应解释器
- TaskAction 新增可选 language，旧任务按解释器推断；补 Shell 执行测试、语言切换单测与 Playwright 用例

backend/tests/runs.rs

@@ -1,4 +1,4 @@
-use std::time::Duration;
+use std::{fs, time::Duration};
 
 use axum::{
     Json, Router,
@@ -201,6 +201,58 @@ async fn wait_for_run(router: &Router, run_id: i64) -> Value {
     panic!("run {run_id} did not reach a terminal state");
 }
 
+#[tokio::test]
+async fn shell_language_runs_batch_file_with_cmd_c() {
+    let app = test_app().await;
+    let working_dir = app._temp_dir.path().to_string_lossy().into_owned();
+    fs::write(
+        app._temp_dir.path().join("hello.bat"),
+        "@echo off\r\necho shell-language-ok\r\n",
+    )
+    .expect("batch file should be written");
+
+    let mut task = script_task(
+        "shell_task",
+        &working_dir,
+        "cmd.exe",
+        "hello.bat",
+        vec![],
+        "0 0 2 * * *",
+        10,
+    );
+    task["action"]["language"] = json!("shell");
+    let create_response = send_json(&app.router, Method::POST, "/api/v1/tasks", Some(task)).await;
+    assert_eq!(create_response.status(), StatusCode::CREATED);
+
+    let run_response = send_json(
+        &app.router,
+        Method::POST,
+        "/api/v1/tasks/shell_task/run",
+        None,
+    )
+    .await;
+    assert_eq!(run_response.status(), StatusCode::ACCEPTED);
+    let run = response_json(run_response).await;
+    let run_id = run["id"].as_i64().expect("run id should be an integer");
+
+    let completed = wait_for_run(&app.router, run_id).await;
+    assert_eq!(completed["status"], "succeeded");
+    let log_response = send_json(
+        &app.router,
+        Method::GET,
+        &format!("/api/v1/runs/{run_id}/logs"),
+        None,
+    )
+    .await;
+    let log = response_json(log_response).await;
+    assert!(
+        log["content"]
+            .as_str()
+            .expect("log content should be a string")
+            .contains("shell-language-ok")
+    );
+}
+
 #[tokio::test]
 async fn manual_script_run_captures_exit_code_and_logs() {
     let app = test_app().await;

backend/tests/tasks.rs

@@ -124,6 +124,7 @@ async fn empty_interpreter_defaults_to_python() {
     assert_eq!(response.status(), StatusCode::CREATED);
     let created = response_json(response).await;
     assert_eq!(created["action"]["interpreter"], "python.exe");
+    assert_eq!(created["action"]["language"], "python");
 }
 
 #[tokio::test]