feat(flow): input feather, center puppet, smiley nav, arc buttons

- Input bar: show bouncing feather icon while typing (circle static); send
  after pause or on submit; debounced isTyping state
- Move puppet to center empty state (replacing feather); hide when there
  are messages
- Add smiley button next to mic; same as Talk (web: location, native: modal)
- Puppet actions: place four buttons in arc above puppet with icons; increase
  spacing between buttons and puppet

src/components/puppet/PuppetView.tsx

@@ -51,7 +51,7 @@ export function PuppetView({ action, isTalking }: PuppetViewProps) {
     const loop = Animated.loop(
       Animated.sequence([
         Animated.timing(smileScale, {
-          toValue: 1.12,
+          toValue: 1.18,
           duration: 400,
           useNativeDriver: true,
           easing: Easing.out(Easing.ease),
@@ -314,26 +314,26 @@ const styles = StyleSheet.create({
     backgroundColor: '#0c4a6e',
   },
   mouthSmile: {
-    width: 22,
-    height: 6,
-    borderBottomLeftRadius: 11,
-    borderBottomRightRadius: 11,
+    width: 28,
+    height: 10,
+    borderBottomLeftRadius: 14,
+    borderBottomRightRadius: 14,
     borderTopLeftRadius: 0,
     borderTopRightRadius: 0,
   },
   mouthOpen: {
     width: 18,
-    height: 6,
+    height: 8,
     top: BODY_SIZE * 0.51,
     borderRadius: 3,
     backgroundColor: 'rgba(12, 74, 110, 0.9)',
   },
   mouthBigSmile: {
-    width: 32,
-    height: 10,
-    top: BODY_SIZE * 0.51,
-    borderBottomLeftRadius: 16,
-    borderBottomRightRadius: 16,
+    width: 42,
+    height: 24,
+    top: BODY_SIZE * 0.50,
+    borderBottomLeftRadius: 21,
+    borderBottomRightRadius: 21,
     borderTopLeftRadius: 0,
     borderTopRightRadius: 0,
   },