The packaged binary panicked on startup ("svg load: Unrecognized image file
format"): asset SVGs were referenced by their build-time CARGO_MANIFEST_DIR
path (absent on an installed system, so read_to_string returned empty bytes),
and gdk::Texture::from_bytes can no longer decode SVG since librsvg dropped its
gdk-pixbuf loader.
- include_str! the SVGs into the binary (no runtime asset files)
- rasterise via resvg/tiny-skia into a gdk::MemoryTexture (no system loader)
