Make test runner auto detect runnable tests

The current test runner requires each test file to be explicitly added to a list of tests in the run.lua file, this has created a point of pain when merging multiple branches together as it is common to have conflicts in this file. Change the runner to auto detect the tests needed to be run so we no longer get the merging issues.

先閱讀 run.lua，追蹤目前明確的測試清單如何組建與執行。執行現有的測試執行器以確認其目前的行為，接著驗證可執行的測試檔案是否會被探索並執行，而不需要編輯中央清單，包括新增測試檔案時也是如此。

由索引模型根據 Issue 內容生成。