Ports main's #7999/#7893 failure policy onto the v2 turn-item work log:
output text that reports a failure (command not found, ENOENT, nonzero
exit markers) now flags a row even when the provider item completed
"successfully", while the rendered row judges only its displayed result —
a command that merely greps for failure strings stays calm. Success now
also requires the failure check to pass, so recovered failures no longer
get the blue check.

The server half of #7893 needs no port: CodexAdapterV2 already projects
item.status directly, so a failed item never masquerades as completed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>