A nested def's own for variable was taken as a capture

Found 2026-10-20 in Vloot: def paint(colour): for w in widgets: ... nested in a function that also has a w was given the capture list w widgets. A lambda that forwarded paint's captures had been built from the earlier list (widgets), so its call came one argument short.

Cause: in Python for lexes as a plain tkIdent (PyParseFor asks PyIsIdent('for')), but PyBodyBindsLocal and PyInUnpackTarget scan the UNPARSED body for tkFor. The for nm in binding (and for a, b in) was never seen, so the name was treated as a capture whenever the enclosing scope had one.

Fix: PyTokIsFor accepts either form; both scans use it.

Test: test_nilpy_lambda_capturing_a_str_calls_a_def (hover_rows, pairs_total).