The tag pinned jian at 453bd70 (2026-08-08), but the code calls
LayoutScene::node_path_at_doc_point_for_fill, only added to jian in 2edfc36
(2026-08-09) — so `nix build …#openpencil` failed to compile. The committed
flake.lock was also older than the flake.nix pins for jian and casement, so
`nix flake show` errored without --no-write-lock-file.
Bump the jian input to 2edfc36 and regenerate flake.lock (jian + casement now
match their flake.nix pins, with correct narHashes). Fixes#208.