Make the development test setup reproducible from a clean checkout

[user01010111]

The repository tracks scripts/tests as a symbolic link to ../../tests, but that target is not included in the repository.

scripts/main.lua looks for scripts/tests/RmTestRunner.lua and loads it when present. On a clean checkout, the link is broken and the runner is unavailable, so contributors cannot run the intended tests.

This does not affect normal gameplay or packaged releases because the test runner is optional and the development link is excluded from release archives. The problem is limited to development and contribution work.

Steps to confirm:

1. Clone the repository into a clean directory.
2. Inspect scripts/tests.
3. The link points to ../../tests.
4. The target directory and RmTestRunner.lua are not present.

It would be helpful to clarify how the tests are intended to be used. Possible options include:

• Keeping the tests in the repository
• Documenting where contributors can obtain or place them
• Removing the tracked link if the tests are only part of a private development setup

Once the test setup is reproducible, a small validation workflow for Lua syntax, XML parsing, and regression tests could be considered separately.

Relevant files:

• scripts/tests
• scripts/main.lua