[Feature]: Add Jetbrains junie cli Support

[L1ghtn1ng]

Before submitting

• I searched existing issues and did not find a duplicate.
• I am describing a concrete problem or use case, not just a vague idea.

Area

Not sure

Problem or use case

I would like t3 code to have support for jetbrains junie cli, its their harness like opencode for example

Proposed solution

I think as you use the acp protocol for things it should be simple enough to integrate in theory as junie has acp support.

Why this matters

Missing support for a well know harness and would be a good addition

Smallest useful scope

Having it be supported like codex for example

Alternatives considered

N/A

Risks or tradeoffs

None that I can think off

Examples or references

https://junie.jetbrains.com/docs/junie-cli-acp.html

Contribution

• I would be open to helping implement this.