docs(i18n): address ds-review-bot on the v4 restoration

解析器：三段闭合标签改为行首锚定（正文提及 </translation> 不再截
断）、重复段全文扫描并校验段序（补两条回归测试）。切换行：v4 模板
保持字面占位不变，资产文档写明全新配对由流水线在解析后按目标文件
名机械插入、配对门禁兜底。加粗后空格限定于字母/数字/汉字、标点前
一律不加；RFC 2119 关键词改为保留源侧强调标记（斜体归斜体、加粗
归加粗）。i18n README 双侧同步 v4 契约描述（不再承诺 CDATA 协议与
规则注入）并重录配对。

scripts/translation-prompt.spec.ts

@@ -42,9 +42,19 @@ describe('translation response sections', () => {
     expect(parseTranslationResponse(fenced).final).toBe('A')
   })
 
+  it('keeps an inline close tag inside prose from terminating the section', () => {
+    const doc = { translation: 'the wire format uses </translation> as its close tag', review: '- 无修正', final: 'F' }
+    expect(parseTranslationResponse(renderTranslationResponse(doc))).toEqual(doc)
+  })
+
+  it('rejects a duplicate section appearing before final', () => {
+    const early = '<translation>\nA\n</translation>\n<translation>\nB\n</translation>\n<review>\nR\n</review>\n<final>\nF\n</final>'
+    expect(() => parseTranslationResponse(early)).toThrow(/duplicate <translation>/)
+  })
+
   it('rejects missing, unterminated, or duplicated sections', () => {
-    expect(() => parseTranslationResponse('<translation>\nA\n</translation>')).toThrow(/missing <review>/)
-    expect(() => parseTranslationResponse('<translation>\nA')).toThrow(/unterminated <translation>/)
+    expect(() => parseTranslationResponse('<translation>\nA\n</translation>')).toThrow(/missing or unterminated <review>/)
+    expect(() => parseTranslationResponse('<translation>\nA')).toThrow(/missing or unterminated <translation>/)
     const dup = '<translation>\nA\n</translation>\n<review>\nR\n</review>\n<final>\nF\n</final>\n<final>\nG\n</final>'
     expect(() => parseTranslationResponse(dup)).toThrow(/duplicate <final>/)
   })