Based entirely on the work of @robzolkos in #5711. That attempt was
adapted to better fit the standard templating system while also adding
color mixing for use in other themes.
The three components were three takes on the same shape \u2014 a clickable
rectangle with text/icon, a hot/hover state, an optional persistent
border, and an optional 'selected' or 'active' highlight. CursorPill
was a 30-line PillButton wrapper that added a hovered() signal;
ChoiceButton was effectively PillButton with selected: bool painting
an accent fill+border.
Collapse them into a single qs.Ui.Button. State flags compose
independently:
hasCursor / hover hot fill
active persistent foreground-tint fill
selected accent fill + accent border
bordered: true persistent 1px idle border (form primaries)
focusable: true Tab focus paints the accent ring
pressed pressed fill
The hovered(bool) signal is now built-in, so CursorPill's wrapper is
unnecessary. ButtonGroup wraps a Row+Repeater for the form-style
'pick one of N' pattern; panel-cursor-driven cases still compose
Buttons directly in a Row with per-instance hasCursor wiring.
Theme tokens move into a new [style] section in shell.toml:
border-width = 1
focus-border-width = 3
idle-border-alpha = 0.4
hot-fill-alpha = 0.08
selected-fill-alpha = 0.18
pressed-fill-alpha = 0.22
focus-fill-alpha = 0.22
Style.qml parses these out of the same shell.toml [font] / [bar]
already reads, and exposes pre-computed Style.hotFill / selectedFill /
pressedFill / idleBorderColor / selectedAccentFill / borderWidth +
the existing focusBorder* tokens. Themes that don't ship a [style]
section get the previous defaults unchanged.
Dev gallery consolidates three sections (PillButton, CursorPill,
ChoiceButton) into Button + ButtonGroup, with the cursor model
sections renamed accordingly.
