test(calculate-version): 補強測試覆蓋並拆分混合測試案例

- 新增 logger section/info/error 的輸出格式測試
- config 補上 GITEA_REPOSITORY 驗證測試，並拆分 isUnset/requireEnv 的正反例
- version 補回 compareVersionArrays 的 major 跨區段比較案例

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

app/test/logger.test.js

@@ -0,0 +1,55 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const logger = require('../logger');
+
+// 暫時攔截 process.stdout.write，回傳期間內寫出的內容
+function captureStdout(fn) {
+    const original = process.stdout.write;
+    let out = '';
+    process.stdout.write = (chunk) => { out += chunk; return true; };
+    try {
+        fn();
+    } finally {
+        process.stdout.write = original;
+    }
+    return out;
+}
+
+// 暫時攔截 process.stderr.write，回傳期間內寫出的內容
+function captureStderr(fn) {
+    const original = process.stderr.write;
+    let out = '';
+    process.stderr.write = (chunk) => { out += chunk; return true; };
+    try {
+        fn();
+    } finally {
+        process.stderr.write = original;
+    }
+    return out;
+}
+
+test('section 以主/次分隔線包夾標題輸出至 stdout', () => {
+    const out = captureStdout(() => logger.section('參數檢查'));
+    const line = '='.repeat(50);
+    const subline = '-'.repeat(50);
+    assert.equal(out, `\n${line}\n參數檢查\n${subline}\n`);
+});
+
+test('info 以 [info] 前綴與換行輸出至 stdout', () => {
+    const out = captureStdout(() => logger.info('IS_BETA=false'));
+    assert.equal(out, '[info] IS_BETA=false\n');
+});
+
+test('error 以 [error] 前綴與換行輸出至 stderr', () => {
+    const out = captureStderr(() => logger.error('GITEA_SERVER_URL 未設定'));
+    assert.equal(out, '[error] GITEA_SERVER_URL 未設定\n');
+});
+
+test('error 僅輸出不終止行程，呼叫後仍可繼續執行', () => {
+    let reached = false;
+    captureStderr(() => { logger.error('still alive'); reached = true; });
+    assert.equal(reached, true);
+});