Diagnostics have carried a `fix` field all along, but the CLI renderer
never printed it — the suggestion was only reachable through --json. The
actionable half of every validation failure was invisible to the person
running the command.
print_diagnostics now emits the fix as a dim-labelled continuation line
under any diagnostic that has one, at both error and warning severity.
Gating it behind --verbose would defeat the point, and printing it only
for errors would read as "this warning has no fix" — the warning
suggestions are useful on their own. Diagnostics that set no fix simply
omit the line.
The severity match moved into print_diagnostic so the fix line is
appended once in the loop rather than copied into all five arms; the
rest of the diff is reindentation.
print_diagnostics is shared by validate, preflight, graph, exec, and
dry-run, so this covers all five. Eleven inline snapshots across four
files gain a fix line; every change is additive.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>