🗑️ remove(test): drop skill regression suites

- delete the gitea-fix-ci credential suite (13 cases covering secret
  redaction, cross-origin redirect refusal and header injection); the
  script keeps those behaviours but nothing guards them now
- stop pointing at the tsl-syntax lookup recall suite from data/README.md:
  that suite was never committed and is now deleted, leaving --check as the
  only guard for lexicon/page correspondence

skills/tsl-syntax-reference/data/README.md

@@ -26,8 +26,8 @@
 
 ```bash
 python scripts/lookup.py --check
-python -m unittest test.test_tsl_syntax_lookup_recall   # 在仓库根目录运行
 ```
 
-新增参考页时，除补词表外还须在回归测试里补一条真实问法
-（`test/test_tsl_syntax_lookup_recall.py` 的 `RECALL_CASES`）。
+`--check` 会校验 `page_intent_aliases` 的键与 `references/` 参考页一一对应：
+键指向不存在的页、或某页没有自然语言入口都会报错。新增参考页时必须同时
+在这里补一条页级意图短语。