Fixes #11722

When local exec commands are terminated by SIGPIPE (exit code 141) or SIGKILL (exit code 137), they were incorrectly reported as "API billing errors".

Changes

• Added isProcessTerminationError() function to detect SIGPIPE/SIGKILL signals
• Modified isBillingErrorMessage() to exclude process termination errors
• Users now see appropriate error messages instead of misleading billing warnings

Testing

1. Run a command that triggers SIGPIPE: curl -I https://example.com 2>&1 | head -n 5
2. Verify the error message mentions process termination, not billing

Feedback welcome!

Greptile Summary

Added isProcessTerminationError() function to detect SIGPIPE (exit code 141/signal 13) and SIGKILL (exit code 137/signal 9) errors, and modified isBillingErrorMessage() to exclude these process termination errors, preventing them from being incorrectly reported as API billing errors.

Confidence Score: 4/5

• This PR is safe to merge with low risk
• The implementation correctly identifies process termination signals and prevents false positives in billing error detection. The logic is sound, covers all relevant signal codes (both numeric and name-based), and the change is narrowly scoped to fix a specific issue.
• Consider adding unit tests for isProcessTerminationError() to verify all signal detection patterns work correctly

_{Last reviewed commit: 7e90325}