Broadens the previous J/T/U fix: fossil's next_token() returns a non-NULL empty string whenever a card ends in a space, on any letter, and each card's own validation decides. C is the common case — 1,009 empty-comment artifacts across sqlite and tcl were rejected and demoted to content. Interior empty tokens stay malformed, and arity still gates the rest. check-in: 5773517bde user: dmestas tags: trunk