F1: log form searches only bytes after WAIT_FROM, so a stale done line in a
reused log is ignored (also makes the per-check cost independent of log size).
F2: pid form prints GONE (no completion evidence). F4: invalid ERE is exit 3.
Mode 100755 recorded for wait-on.sh; other tools/ scripts are still 100644.
F5, F6, F7 recorded as known limitations in the header. Fixtures added.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>