fix(coding-agent): prepare v0.83.0-kkl.4

[quick-ricon]

Summary

• bump all KKL Pi package, lock, shrinkwrap, and install-lock versions from 0.83.0-kkl.3 to 0.83.0-kkl.4
• prepare the merged built-in message renderer API and model-catalog baseline repair for the next KKL fork release

Validation

• exact 61 substitutions across the expected 12 release files
• npm run check
• git diff --check
• signed source commit verified
• merged-main CI run 31025567573 passed on exact base 8d5780573

The first local check attempt lacked the ignored hydrated provider catalog in the new worktree; rerunning with the same catalog validated on green main passed. No changelog was edited because this uses the dedicated KKL fork release workflow rather than the upstream npm release path.

This PR is AI-generated.