test(release-cleanup): 新增 validate/releases/tags/gitea-client 單元測試

以 node:test 內建測試器涵蓋純函式(isEmptyOrNull/requireValue/requireInteger、
selectReleasesToDelete、categorizeTags)與 GiteaClient 分頁/刪除邏輯,共 19 項測試。

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

app/test/validate.test.js

@@ -0,0 +1,37 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { isEmptyOrNull, requireValue, requireInteger } from '../validate.js'
+
+test('isEmptyOrNull 對空值回傳 true', () => {
+  assert.equal(isEmptyOrNull(''), true)
+  assert.equal(isEmptyOrNull(null), true)
+  assert.equal(isEmptyOrNull(undefined), true)
+  assert.equal(isEmptyOrNull('null'), true)
+})
+
+test('isEmptyOrNull 對有效值回傳 false', () => {
+  assert.equal(isEmptyOrNull('value'), false)
+  assert.equal(isEmptyOrNull('0'), false)
+  assert.equal(isEmptyOrNull(0), false)
+})
+
+test('requireValue 對空值丟出錯誤', () => {
+  assert.throws(() => requireValue('NAME', ''), /NAME is required/)
+  assert.throws(() => requireValue('NAME', 'null'), /NAME is required/)
+})
+
+test('requireValue 對有效值不丟出錯誤', () => {
+  assert.doesNotThrow(() => requireValue('NAME', 'value'))
+})
+
+test('requireInteger 接受非負整數', () => {
+  assert.doesNotThrow(() => requireInteger('KEEP_COUNT', '0'))
+  assert.doesNotThrow(() => requireInteger('KEEP_COUNT', '10'))
+  assert.doesNotThrow(() => requireInteger('KEEP_COUNT', 5))
+})
+
+test('requireInteger 拒絕非整數或負數', () => {
+  assert.throws(() => requireInteger('KEEP_COUNT', '-1'), /non-negative integer/)
+  assert.throws(() => requireInteger('KEEP_COUNT', '1.5'), /non-negative integer/)
+  assert.throws(() => requireInteger('KEEP_COUNT', 'abc'), /non-negative integer/)
+})