pythontk v0.9.18

• 2026-08-12 — _sized_encoder_buffer reads the format set it belongs to instead of re-listing it. The JPEG buffer guard hardcoded ("jpg", "jpeg") three lines from the ALWAYS_LOSSY_FORMATS constant added in the same change — two lists to keep in step, when the constant already names exactly the containers whose writer takes the quality and subsampling that overflow Pillow's guess. CancelScope.consumed also gains coverage of its own (test_cancel_scope.py 34 → 40): it was pinned only through uitk's dispatcher, so the property's actual contract went untested where it lives — a checkpoint that never reports a stop does not consume it, one that does (either style) consumes it, a parent's cancel is consumed at a child's checkpoint, and reset() clears it.