[jules] enhance: Add skeleton loading for mobile home screen

.Jules/changelog.md

@@ -7,6 +7,14 @@
 ## [Unreleased]
 
 ### Added
+- **Mobile Skeleton Loading:** Implemented a skeleton loading state for the Home screen groups list.
+  - **Features:**
+    - Created a reusable `Skeleton` component using `Animated` for pulsing opacity.
+    - Created `GroupListSkeleton` to mimic the exact layout of group cards.
+    - Replaced the generic `ActivityIndicator` spinner with the skeleton loader for a smoother UX.
+    - Matches `react-native-paper` theme colors (uses `surfaceVariant`).
+  - **Technical:** Created `mobile/components/ui/Skeleton.js`, `mobile/components/skeletons/GroupListSkeleton.js`. Updated `mobile/screens/HomeScreen.js`.
+
 - **Password Strength Meter:** Added a visual password strength indicator to the signup form.
   - **Features:**
     - Real-time strength calculation (Length, Uppercase, Lowercase, Number, Symbol).

.Jules/knowledge.md

@@ -299,6 +299,27 @@ Commonly used components:
 - `<Portal>` and `<Modal>` for overlays
 - `<ActivityIndicator>` for loading states
 
+### Skeleton Loading Pattern
+
+**Date:** 2026-02-12
+**Context:** Implemented in `HomeScreen` for better perceived performance.
+
+Use `mobile/components/ui/Skeleton.js` for building loading states:
+1. **Base Component:** `<Skeleton width={100} height={20} />`
+2. **Animation:** Uses `Animated.loop` for pulsing opacity (0.3 <-> 1.0).
+3. **Theming:** Automatically uses `theme.colors.surfaceVariant`.
+4. **Layout:** Combine multiple `Skeleton` components inside a container (e.g., `GroupListSkeleton`) that mimics the actual content layout (e.g., inside a `Card`).
+
+**Example:**
+```jsx
+<Card>
+  <Card.Title
+    title={<Skeleton width={150} height={20} />}
+    left={(props) => <Skeleton width={40} height={40} borderRadius={20} />}
+  />
+</Card>
+```
+
 ### Safe Area Pattern
 
 **Date:** 2026-01-01

.Jules/todo.md

@@ -57,11 +57,12 @@
   - Impact: Native feel, users can easily refresh data
   - Size: ~150 lines
 
-- [ ] **[ux]** Complete skeleton loading for HomeScreen groups
-  - File: `mobile/screens/HomeScreen.js`
-  - Context: Replace ActivityIndicator with skeleton group cards
+- [x] **[ux]** Complete skeleton loading for HomeScreen groups
+  - Completed: 2026-02-12
+  - Files: `mobile/screens/HomeScreen.js`, `mobile/components/ui/Skeleton.js`, `mobile/components/skeletons/GroupListSkeleton.js`
+  - Context: Created reusable Skeleton component and GroupListSkeleton to replace spinner
   - Impact: Better loading experience, less jarring
-  - Size: ~40 lines
+  - Size: ~80 lines
   - Added: 2026-01-01
 
 - [x] **[a11y]** Complete accessibility labels for all screens

mobile/components/skeletons/GroupListSkeleton.js

@@ -0,0 +1,27 @@
+import React from 'react';
+import { View } from 'react-native';
+import { Card } from 'react-native-paper';
+import Skeleton from '../ui/Skeleton';
+
+const GroupListSkeleton = () => {
+  // Render 4 skeleton items to fill the screen
+  return (
+    <View style={{ padding: 16 }} accessibilityLabel="Loading groups">
+      {[1, 2, 3, 4].map((i) => (
+        <Card key={i} style={{ marginBottom: 16 }}>
+          <Card.Title
+            title={<Skeleton width={150} height={20} />}
+            left={(props) => (
+              <Skeleton width={40} height={40} borderRadius={20} />
+            )}
+          />
+          <Card.Content>
+            <Skeleton width={220} height={16} style={{ marginTop: 4 }} />
+          </Card.Content>
+        </Card>
+      ))}
+    </View>
+  );
+};
+
+export default GroupListSkeleton;

mobile/components/ui/Skeleton.js

@@ -0,0 +1,45 @@
+import React, { useEffect, useRef } from 'react';
+import { Animated, View } from 'react-native';
+import { useTheme } from 'react-native-paper';
+
+const Skeleton = ({ width, height, borderRadius, style }) => {
+  const theme = useTheme();
+  const opacity = useRef(new Animated.Value(0.3)).current;
+
+  useEffect(() => {
+    const animation = Animated.loop(
+      Animated.sequence([
+        Animated.timing(opacity, {
+          toValue: 1,
+          duration: 800,
+          useNativeDriver: true,
+        }),
+        Animated.timing(opacity, {
+          toValue: 0.3,
+          duration: 800,
+          useNativeDriver: true,
+        }),
+      ])
+    );
+    animation.start();
+
+    return () => animation.stop();
+  }, [opacity]);
+
+  return (
+    <Animated.View
+      style={[
+        {
+          width,
+          height,
+          borderRadius: borderRadius || 4,
+          backgroundColor: theme.colors.surfaceVariant,
+          opacity,
+        },
+        style,
+      ]}
+    />
+  );
+};
+
+export default Skeleton;

mobile/screens/HomeScreen.js

@@ -13,6 +13,7 @@ import {
 import HapticButton from '../components/ui/HapticButton';
 import HapticCard from '../components/ui/HapticCard';
 import { HapticAppbarAction } from '../components/ui/HapticAppbar';
+import GroupListSkeleton from '../components/skeletons/GroupListSkeleton';
 import * as Haptics from "expo-haptics";
 import { createGroup, getGroups, getOptimizedSettlements } from "../api/groups";
 import { AuthContext } from "../context/AuthContext";
@@ -257,9 +258,7 @@ const HomeScreen = ({ navigation }) => {
       </Appbar.Header>
 
       {isLoading ? (
-        <View style={styles.loaderContainer}>
-          <ActivityIndicator size="large" />
-        </View>
+        <GroupListSkeleton />
       ) : (
         <FlatList
           data={groups}
@@ -289,11 +288,6 @@ const styles = StyleSheet.create({
   container: {
     flex: 1,
   },
-  loaderContainer: {
-    flex: 1,
-    justifyContent: "center",
-    alignItems: "center",
-  },
   list: {
     padding: 16,
   },