Read anchors resolve like file_changes (r<k> rows, MISSING when absent at
base), anchors with a symbol must hold it in the mapped window or gain
SYMBOL_MISSING, and one capped git-grep caller list per symbol follows the
windows within --max-lines. Specs without reads or symbols print what v1 did.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>