Wire the previously-unused ColorSwatchRow into the compose FormattingToolbar
with two new controls: a font-color button applying RichStyle.FontColor and a
highlight button applying RichStyle.Highlight over the selection. Each opens a
ColorPickerDialog built on the shared ColorSwatchRow (~8 font colors; yellow /
green / cyan / pink highlighter markers), with a "no color"/"none" entry that
clears the style outright via a new clearStyle op. Buttons reflect the current
selection's color and carry accessible onClickLabels; swatches carry their own
contentDescriptions.
Closes#74Closes#75
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>