each_paragraph_run skipped the empty paragraph after a closing line break, so a
selected object whose last paragraph's Auto Leading differed showed one Leading
instead of a mixed (blank) field. With no range, that paragraph now counts with
the style of the run before it. Covered by
leading_field_counts_the_final_empty_paragraph.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014gCpjL3yUhaH3jRp7ksufh