Use masked Kirigami icons with explicit theme colors for shell controls so the Shift icon theme renders reliably across light and dark surfaces. Replace the status-bar battery helper with theme icon names so battery glyphs also come from org.shift.icons.
Give the app-thumbnail close affordance a symbolic white X on a dark circular backing so it remains visible over previews.
qmllint shipped with Qt 6.12 segfaults on the inline component
definition inside RunningAppsPanel.qml, breaking the
suse_tumbleweed_qt612 KDE Invent CI job. Move PanelIconButton out
to a sibling RunningAppsPanelButton.qml so qmllint never has to
parse a UiInlineComponent here.
The extracted file inlines its own colour-mix helper to keep it
self-contained and avoid leaking RunningAppsPanel internals.
