fix(macos): statically link liblzma so the app launches (#56)

vtkio (via truck-meshalgo → xz2 → lzma-sys) linked the system liblzma
dynamically, baking a Homebrew path (/opt/homebrew/.../liblzma.5.dylib)
into the macOS binary. The .app then crashed on launch on any Mac
without that exact library. Enable lzma-sys's `static` feature so
liblzma is compiled from the bundled source into the binary, making it
self-contained on every platform (verified: no dynamic liblzma link).

Co-Authored-By: Claude Opus 4.8 <[email protected]>

Cargo.lock

@@ -23,6 +23,7 @@ dependencies = [
  "iced",
  "image",
  "inventory",
+ "lzma-sys",
  "open",
  "printpdf",
  "rayon",