Order by (ts, chunk start, chunk first event id, position) so the window does
not depend on its anchor. Each read asks for the held chunks at the edge in
addition, so a run of chunks at one start ms cannot fill a read with held ones;
the no-gain early stop is gone. Search and window print a body's line breaks as
\n. Tests pin ties, caps, dedupe, the unreached flag and non-chat points.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Eureka
0d5efeeace