Switched from the monochrome emoji font to color: NotoColorEmoji's
embedded CBDT bitmap glyphs, rasterized once at their native 109px
size and scaled to the target row height (unlike normal vector text,
color bitmap glyphs aren't stored at arbitrary sizes). Confirmed by
rendering an actual agenda row through the real quantizer that the
dithered-to-6-color result still reads clearly, not just muddy noise.
Falls back to the monochrome font if a deployment's Pillow/FreeType
wasn't built with embedded color bitmap support, so this degrades
instead of crashing or showing nothing.
