feat(overview-artifact): 產生可預覽總覽與截圖 fallback

scripts/lib.js

@@ -422,6 +422,31 @@ export async function giteaRequest(login, method, path, { body, query } = {}) {
   const text = await response.text();
   return { status: response.status, body: text ? safeJson(text) : null };
 }
+/**
+ * 上傳 Gitea issue attachment。這是唯一的 multipart HTTP 出口。
+ * @param {{base:string, token:string}} login
+ * @param {string} path
+ * @param {string} filePath
+ * @param {string} fileName
+ * @returns {Promise<{status:number, body:any}>}
+ */
+export async function giteaUpload(login, path, filePath, fileName) {
+  const form = new FormData();
+  form.append('attachment', new Blob([readFileSync(filePath)]), fileName);
+  const url = new URL(`${login.base}${path}`);
+  let response;
+  try {
+    response = await fetch(url, {
+      method: 'POST',
+      headers: { Authorization: `token ${login.token}`, Accept: 'application/json' },
+      body: form,
+    });
+  } catch (cause) {
+    throw new ScriptError('NETWORK_ERROR', `連不上 Gitea（POST ${path}）：${cause.message}`);
+  }
+  const text = await response.text();
+  return { status: response.status, body: safeJson(text) };
+}
 
 /**
  * 把「非預期狀態碼」收斂成帶狀態碼的錯誤，成功則回傳 body。