test(release-cleanup): 補上一般網路錯誤與空陣列邊界測試

新增 fetchAllPages 在 fetch 拋一般網路錯誤時向外拋出的測試,以及
selectReleasesToDelete 對空陣列回傳空陣列的測試。測試共 67 項全數通過。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/test/gitea-client.test.js

@@ -112,6 +112,17 @@ test('fetchAllPages 在 fetch 因逾時拋出 AbortError 時向外拋出', async
   )
 })
 
+test('fetchAllPages 在 fetch 拋出一般網路錯誤時向外拋出', async () => {
+  globalThis.fetch = async () => {
+    throw new TypeError('fetch failed: ECONNREFUSED')
+  }
+  const client = new GiteaClient({})
+  await assert.rejects(
+    () => client.fetchAllPages('https://example.com/api'),
+    /fetch failed|ECONNREFUSED/,
+  )
+})
+
 test('fetchAllPages 在頁數超過 MAX_PAGES 時中止以避免無限迴圈', async () => {
   // 永遠回傳非空陣列,模擬 API 不以空陣列結尾的異常情形
   globalThis.fetch = async () => jsonResponse([{ id: 1 }])

app/test/releases.test.js

@@ -19,6 +19,11 @@ test('selectReleasesToDelete 在數量不超過保留數時回傳空陣列', ()
   assert.deepEqual(selectReleasesToDelete(releases, 5), [])
 })
 
+test('selectReleasesToDelete 對空陣列回傳空陣列', () => {
+  assert.deepEqual(selectReleasesToDelete([], 1), [])
+  assert.deepEqual(selectReleasesToDelete([], 0), [])
+})
+
 test('selectReleasesToDelete 在 keepCount 為 0 時刪除全部(由新到舊)', () => {
   const toDelete = selectReleasesToDelete(releases, 0)
   assert.deepEqual(