PaperMod variants differ in where extend_head.html lives. When themes/PaperMod/layouts/partials/extend_head.html is unavailable, font setup now falls back to themes/PaperMod/layouts/_partials/extend_head.html instead of failing.

• Fallback behavior in custom font setup

  • Updated head-file write flow in internal/hugogenerator/hugo_custom_font.go.
  • setupFont now attempts the primary path first, and retries with _partials only when the primary write fails due to missing path.

• Coverage for both layout variants

  • Added internal/hugogenerator/hugo_custom_font_test.go with focused cases for:
    • primary layouts/partials path present
    • fallback layouts/_partials path present while primary path is absent

• Implementation shape

  • Introduced a dedicated helper to centralize head-file write + fallback handling.

err := appendFile(filepath.Join(siteDir, _outputHeadFile), data)
if err == nil || !errors.Is(err, os.ErrNotExist) {
    return err
}
return appendFile(filepath.Join(siteDir, _outputHeadFileFallback), data)