Support list file input for `CF_EXCLUDE_MODS` and `CF_INCLUDE_MODS`

[Carlomos7]

Enhancement Type

Improve an existing feature

Describe the enhancement

It would be useful if CF_EXCLUDE_MODS and CF_INCLUDE_MODS could support the @file syntax, similar to how CURSEFORGE_FILES: "@/extras/cf-mods.txt" works.

This would help with managing longer mod include/exclude lists in a cleaner and more maintainable way, especially in shared or version-controlled environments.

[itzg]

Now that I see both lists mentioned, that was basically the idea of the CF_EXCLUDE_INCLUDE_FILE env var:

For more complex scenarios, global and per modpack exclusions can be declared in a container-accessible JSON file and referenced with CF_EXCLUDE_INCLUDE_FILE. By default, the file bundled with the image will be used, but can be disabled by setting this to an empty string. The schema of this file is documented here.

From https://docker-minecraft-server.readthedocs.io/en/latest/types-and-platforms/mod-platforms/auto-curseforge/#exclude-client-mods

The downside is that the given file fully replaces the default file maintained with the image. You'll probably want to start from that file and add the extras.