Gate-review F4: two known blind spots were undocumented — (1) marker-only
drift (env-marker changes with identical pins) is invisible to the pin
diff, (2) direct-URL requirement lines are skipped by the old parser /
now fail loudly instead of being compared. Both disclosed in the module
docstring with guidance; no behavior change.
RED->GREEN: docs-only finding; red evidence is the pre-existing docstring
lacking the disclosure (gate finding itself). Checker behavior and tests
unchanged (15 pass).
Nick
d3c70393dd