check_quotes.py gains --coverage=FILE: on each successful match, atomically
appends one line '{bolt} {section_idx} {start} {end}' to FILE using a single
os.write() call so parallel make invocations don't interleave records.
find_quote() and find_quote_immediate() are updated to return match start
positions (needed to record the covered range, not just the end).
bolt-coverage.py reads the coverage file and reports BOLT text not covered
by any source comment. By default it restricts output to Requirements
sections; --all-sections shows every section. --bolt N restricts to
a single BOLT number.
Exit status is 0 if everything in the selected sections is covered, 1 if
anything is uncovered.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
