mistral CLI v0.4.0

Added

• mistral evals optimize <file> — turn an existing eval file into an optimization
  run that searches for better prompts and parameters (v0; optimizes .py eval
  files). Optional flags:
  • --params — comma-separated params to optimize (e.g. instruction,temperature:0..1);
    defaults to all System.params.
  • --steer — a free-text goal that steers the optimizer's reflective mutator
    (e.g. "reduce hallucinations when the context lacks the answer"), max 4000 chars.
  • --name / --description — human-friendly metadata for the optimization;
    auto-generated from the goal when omitted.
• Install via plain curl, with optional version pinning.

Fixed

• apps init checks that bun is on PATH before shelling out to it, failing with
  a clear error instead of crashing.