Serve lossless WOFF2 browser fonts outside blocking stylesheets

src/assets/fonts/README.md

@@ -12,3 +12,24 @@ Downloaded September 7, 2026. The files are versioned in this repository and cop
 into the production image. Browser and native canvas renderers use the alias
 `Mina Sans`; no system sans-serif font is selected for card text. The native font
 loader fails startup if a required font cannot be registered.
+
+Browser WOFF2 copies are lossless conversions of these exact TTF files using
+FontTools with Brotli; no subsetting is applied. All glyphs and Unicode mappings
+are retained (3,748 glyphs for each Noto Sans weight, 377 for each Instrument
+Serif style). Native canvas keeps using the original TTFs. CSS uses separately
+cacheable `/fonts/browser/*.woff2` URLs so font bytes do not block CSS parsing.
+
+Regenerate with `uv run --with fonttools --with brotli python`:
+
+```python
+from pathlib import Path
+from fontTools.ttLib import TTFont
+for path in Path("src/assets/fonts").glob("*.ttf"):
+    font = TTFont(path)
+    cmap, glyphs = font.getBestCmap(), font.getGlyphOrder()
+    font.flavor = "woff2"
+    font.save(path.with_suffix(".woff2"))
+    restored = TTFont(path.with_suffix(".woff2"))
+    assert restored.getBestCmap() == cmap
+    assert restored.getGlyphOrder() == glyphs
+```