feat(app): add running status ring and lighten status dots

Keep the animated ring phase-locked across hosts and derive its knockout surface from each host's actual interaction state. Align filled status circles at 6px while preserving the larger needs-input alert.

Co-authored-by: Christoph Leiter <christoph@leiter.io>

packages/app/src/subagents/track.tsx

@@ -200,7 +200,10 @@ function SubagentsTrackRow({
       >
         {({ pressed }) => (
           <View style={hovered || pressed ? styles.rowActive : styles.row}>
-            <WorkspaceTabIcon presentation={presentation} />
+            <WorkspaceTabIcon
+              presentation={presentation}
+              backdrop={hovered || pressed ? "surface2" : "surface1"}
+            />
             <Text style={styles.rowLabel} numberOfLines={1}>
               {displayLabel}
             </Text>