fix(inspect): set whole_change granularity when posting a verdict to the trail

Posting the review verdict to a trail failed with 'comments.0.location .granularity: Invalid option' (400): the finding input omitted Location, so an empty granularity was sent. A consolidated verdict isn't tied to a file/line, so set granularity=whole_change (matching the trail finding add path's default). Extracted reviewTrailFindingInput so it's unit tested for granularity + body, and pinned the regression.