feat: 首页改版与 uv / 镜像配置收敛，精简任务数据结构

- 页头只保留品牌与操作图标，三栏改为 1:2:1、容器最宽 1320
- 任务卡片：状态标签移入标题行并缩小，隐藏任务标识，操作行贴内容底边
- uv 配置弹窗：删掉与首页重复的状态条，三段配置改成标签页
- 镜像源：弹窗去掉默认镜像汇总，首页卡片改为展示默认镜像与运行时注入的变量
- 后端：迁移合并为单一基线 0001_init，删掉未生效的 concurrency_policy / retry_*，
  运行触发只剩 schedule / manual；contracts、前端生成类型、README / PLAN 同步

backend/tests/api.rs

@@ -131,6 +131,30 @@ async fn directory_listing_endpoint_returns_subdirectories() {
     );
 }
 
+#[tokio::test]
+async fn directory_listing_endpoint_includes_files_when_requested() {
+    let (app, temp_dir) = test_app().await;
+    let tools = temp_dir.path().join("tools");
+    fs::create_dir_all(tools.join("bin")).expect("bin directory should be created");
+    fs::write(tools.join("uv.exe"), "x").expect("file should be written");
+
+    let uri = format!(
+        "/api/v1/system/directories?path={}&include_files=true",
+        encode_query_path(&tools)
+    );
+    let (status, body) = get_json(&app, &uri).await;
+
+    assert_eq!(status, StatusCode::OK);
+    let entries = body["entries"]
+        .as_array()
+        .expect("entries should be an array");
+    assert_eq!(entries.len(), 2);
+    assert_eq!(entries[0]["name"], "bin");
+    assert_eq!(entries[0]["is_dir"], true);
+    assert_eq!(entries[1]["name"], "uv.exe");
+    assert_eq!(entries[1]["is_dir"], false);
+}
+
 #[tokio::test]
 async fn directory_listing_endpoint_rejects_relative_paths() {
     let (app, _temp_dir) = test_app().await;

backend/tests/uv.rs

@@ -197,6 +197,81 @@ async fn uv_settings_mutations_require_token() {
     assert_eq!(body["code"], "FORBIDDEN");
 }
 
+#[tokio::test]
+async fn uv_mirror_is_saved_with_the_settings_and_drives_both_urls() {
+    let (app, _temp_dir) = test_app().await;
+    let token = auth_token(&app).await;
+
+    let (status, body) = send_json(&app, Method::GET, "/api/v1/uv", None, None).await;
+    assert_eq!(status, StatusCode::OK);
+    assert_eq!(
+        body["mirror_url"],
+        "https://mirrors.ustc.edu.cn/github-release"
+    );
+    assert_eq!(
+        body["uv_download_url"],
+        "https://mirrors.ustc.edu.cn/github-release/astral-sh/uv/LatestRelease"
+    );
+    assert_eq!(
+        body["python_mirror_url"],
+        "https://mirrors.ustc.edu.cn/github-release/astral-sh/python-build-standalone/releases/download"
+    );
+    // 解释器镜像作为默认环境变量出现在列表里，可以被显式覆盖
+    assert_eq!(
+        body["env_defaults"]["UV_PYTHON_INSTALL_MIRROR"],
+        "https://mirrors.ustc.edu.cn/github-release/astral-sh/python-build-standalone/releases/download"
+    );
+
+    // 非法镜像地址会被拒绝
+    let (status, body) = send_json(
+        &app,
+        Method::PUT,
+        "/api/v1/uv",
+        Some(&token),
+        Some(json!({
+            "source": "managed",
+            "mirror_url": "ftp://mirror.example"
+        })),
+    )
+    .await;
+    assert_eq!(status, StatusCode::BAD_REQUEST);
+    assert_eq!(body["field"], "url");
+
+    // 保存自定义镜像：两个下载地址都由它派生
+    let (status, saved) = send_json(
+        &app,
+        Method::PUT,
+        "/api/v1/uv",
+        Some(&token),
+        Some(json!({
+            "source": "managed",
+            "mirror_url": "https://mirror.example/github-release/"
+        })),
+    )
+    .await;
+    assert_eq!(status, StatusCode::OK);
+    assert_eq!(saved["mirror_url"], "https://mirror.example/github-release");
+    assert_eq!(
+        saved["uv_download_url"],
+        "https://mirror.example/github-release/astral-sh/uv/LatestRelease"
+    );
+
+    // 传 null 恢复内置默认
+    let (status, restored) = send_json(
+        &app,
+        Method::PUT,
+        "/api/v1/uv",
+        Some(&token),
+        Some(json!({ "source": "managed", "mirror_url": null })),
+    )
+    .await;
+    assert_eq!(status, StatusCode::OK);
+    assert_eq!(
+        restored["mirror_url"],
+        "https://mirrors.ustc.edu.cn/github-release"
+    );
+}
+
 #[tokio::test]
 async fn uv_download_requires_token() {
     let (app, _temp_dir) = test_app().await;