Note that JShell requires Java 9 or higher.

Some ricochet fixes for Java projects:

• pure Java projects will now use the default Scala versions for declared Scala dependencies (this enables the usage of Scala Toolkit in JShell, for example)
• --repl-init-script-file enables to pass --repl-init-script via a file containing the script
  • this is a workaround for making initialization scripts on Windows
  • currently, it's a low effort implementation which pastes the contents of the script into the REPL (enforcing it has to be a JShell script for Jshell and a Scala script for Scala)
  • a possible follow-up could add extra handling for those scripts (like validation of contents for a given REPL), but I consider it out of scope for this PR

Checklist

• tested the solution locally and it works
• ran the code formatter (scala-cli fmt .)
• ran scalafix (./mill -i __.fix)
• ran reference docs auto-generation (./mill -i 'generate-reference-doc[]'.run)

How much have your relied on LLM-based tools in this contribution?

Extensively, Cursor + Claude

How was the solution tested?

new automated tests