feat(hooks): usePulseAnimation for live indicators

src/hooks/usePulseAnimation.ts

@@ -0,0 +1,44 @@
+import { useEffect } from 'react';
+import {
+  Easing,
+  cancelAnimation,
+  useAnimatedStyle,
+  useSharedValue,
+  withRepeat,
+  withTiming,
+} from 'react-native-reanimated';
+
+type AnimatedStyle = {
+  transform: Array<{ scale: number }>;
+  opacity: number;
+};
+
+export function usePulseAnimation(active: boolean, durationMs = 1600): AnimatedStyle {
+  const scale = useSharedValue(1);
+  const opacity = useSharedValue(active ? 1 : 0.5);
+
+  useEffect(() => {
+    if (active) {
+      scale.value = withRepeat(
+        withTiming(1.4, { duration: durationMs / 2, easing: Easing.out(Easing.quad) }),
+        -1,
+        true,
+      );
+      opacity.value = withRepeat(
+        withTiming(0.55, { duration: durationMs / 2, easing: Easing.inOut(Easing.quad) }),
+        -1,
+        true,
+      );
+    } else {
+      cancelAnimation(scale);
+      cancelAnimation(opacity);
+      scale.value = withTiming(1, { duration: 160 });
+      opacity.value = withTiming(0.5, { duration: 160 });
+    }
+  }, [active, durationMs, scale, opacity]);
+
+  return useAnimatedStyle<AnimatedStyle>(() => ({
+    transform: [{ scale: scale.value }],
+    opacity: opacity.value,
+  }));
+}