fix(cli): tunnel moc exit code so compiler crashes are distinguishable

[Kamirus]

mops build, mops check, mops generate, mops check-stable, and mops test now exit with moc's process exit code instead of always 1. CLI output is unchanged — use $? to tell a compiler crash (2) from a normal user error (1).

Why

moc exits 1 for user errors (type/compile errors, stable-compat mismatch, bad args) and 2 for compiler crashes (uncaught internal error). mops routed every moc failure through cliError, which hard-codes process.exit(1), so a crash looked like any other failure in CI or retry loops.

Before / After

# moc compiler crash
$ mops check; echo "exit=$?"
exit=1    # before
exit=2    # after — stderr unchanged

# normal compile error
$ mops check; echo "exit=$?"
exit=1    # before and after

# moc crash while running tests
$ mops test; echo "exit=$?"
exit=1    # before
exit=2    # after — test output unchanged

What is unchanged

• All CLI output text and test snapshots.
• cliError (exit 1) for config/validation/IO errors; only final moc failure sites use cliExit(code, …).
• Autofix inner loop (--fix), mops watch, mops bench.

[github-actions]

Cursor AI review

👍 APPROVE — looks safe to merge

Category	Assessment	Details
Summary	✅	Adds cliExit to propagate moc's process exit code (notably 2 for compiler crashes vs 1 for user errors) through build, check, generate, check-stable, and test; changelog updated.
Code Quality	✅	Minimal cliExit helper mirrors cliError; call sites consistently use result.exitCode ?? 1; test tracking via optional onClose callback is clean.
Consistency	✅	Config/validation/IO failures still use cliError(1); only final moc failure sites switched, matching stated scope and sibling-command patterns.
Security	✅	No auth, signing, or package-integrity changes; exit-code propagation only.
Tests	⚠️	PR description mentions a cliExit unit test, but no test file is in the diff; existing integration/snapshot coverage is unchanged per PR notes.
Maintainability	✅	Clear separation between CLI validation errors and compiler exit semantics; changelog documents the behavior change.

Verdict

Decision: APPROVE
Risk: Low
Reason: The change is narrowly scoped, correctly tunnels moc exit codes at all intended failure sites, preserves existing output text, and documents the behavior in the changelog. No correctness regressions or production-risk issues were found relative to the base SHA.

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Generated for commit 06526ba

[ggreif]

Looks solid to me and an important feature to have!