Add new screens with proper headers and AppsScreen MiniApps Store

- Add 13 new placeholder screens with back button headers:
  Assembly, Bank, Certificates, Events, Help, Justice,
  Music, Polls, Research, University, VPN, WhatsKURD
- Update AppNavigator with all new screen routes
- Redesign AppsScreen with MiniApps Store:
  - Search bar for app discovery
  - Horizontal scrolling categories
  - Build on Pezkuwichain section with submission form
  - Professional submission modal
  - Featured apps section

mobile/src/screens/VPNScreen.tsx

@@ -0,0 +1,152 @@
+import React from 'react';
+import {
+  View,
+  Text,
+  StyleSheet,
+  SafeAreaView,
+  StatusBar,
+  TouchableOpacity,
+  Platform,
+} from 'react-native';
+import { useNavigation } from '@react-navigation/native';
+import { KurdistanColors } from '../theme/colors';
+
+const VPNScreen: React.FC = () => {
+  const navigation = useNavigation();
+
+  return (
+    <SafeAreaView style={styles.container}>
+      <StatusBar barStyle="dark-content" backgroundColor="#FFFFFF" />
+
+      {/* Header */}
+      <View style={styles.header}>
+        <TouchableOpacity onPress={() => navigation.goBack()} style={styles.backButton}>
+          <Text style={styles.backButtonText}>← Back</Text>
+        </TouchableOpacity>
+        <Text style={styles.headerTitle}>VPN</Text>
+        <View style={styles.placeholder} />
+      </View>
+
+      {/* Content */}
+      <View style={styles.content}>
+        <Text style={styles.icon}>🛡️</Text>
+        <Text style={styles.title}>Coming Soon</Text>
+        <Text style={styles.titleEn}>Decentralized VPN</Text>
+        <View style={styles.messageBox}>
+          <Text style={styles.message}>
+            Decentralized VPN will be available soon!
+          </Text>
+          <Text style={styles.messageEn}>
+            Privacy-first, community-powered VPN network.
+          </Text>
+        </View>
+        <View style={styles.featureList}>
+          <Text style={styles.featureTitle}>Planned Features:</Text>
+          <Text style={styles.featureItem}>• Decentralized relay network</Text>
+          <Text style={styles.featureItem}>• Pay-per-use with HEZ tokens</Text>
+          <Text style={styles.featureItem}>• No-logs policy guaranteed</Text>
+          <Text style={styles.featureItem}>• Community node operators</Text>
+          <Text style={styles.featureItem}>• Bypass censorship</Text>
+        </View>
+      </View>
+    </SafeAreaView>
+  );
+};
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    backgroundColor: '#F5F5F5',
+    paddingTop: Platform.OS === 'android' ? StatusBar.currentHeight : 0,
+  },
+  header: {
+    flexDirection: 'row',
+    justifyContent: 'space-between',
+    alignItems: 'center',
+    paddingHorizontal: 16,
+    paddingVertical: 12,
+    backgroundColor: '#FFFFFF',
+    borderBottomWidth: 1,
+    borderBottomColor: '#E5E5E5',
+  },
+  backButton: {
+    paddingVertical: 4,
+    paddingRight: 8,
+  },
+  backButtonText: {
+    fontSize: 16,
+    color: KurdistanColors.kesk,
+    fontWeight: '500',
+  },
+  headerTitle: {
+    fontSize: 18,
+    fontWeight: 'bold',
+    color: KurdistanColors.reş,
+  },
+  placeholder: {
+    width: 60,
+  },
+  content: {
+    flex: 1,
+    alignItems: 'center',
+    justifyContent: 'center',
+    paddingHorizontal: 32,
+  },
+  icon: {
+    fontSize: 80,
+    marginBottom: 24,
+  },
+  title: {
+    fontSize: 22,
+    fontWeight: 'bold',
+    color: KurdistanColors.reş,
+    textAlign: 'center',
+    marginBottom: 4,
+  },
+  titleEn: {
+    fontSize: 18,
+    color: '#666',
+    textAlign: 'center',
+    marginBottom: 24,
+  },
+  messageBox: {
+    backgroundColor: '#FFFFFF',
+    borderRadius: 16,
+    padding: 20,
+    marginBottom: 24,
+    width: '100%',
+  },
+  message: {
+    fontSize: 15,
+    color: '#444',
+    textAlign: 'center',
+    lineHeight: 24,
+    marginBottom: 12,
+  },
+  messageEn: {
+    fontSize: 14,
+    color: '#888',
+    textAlign: 'center',
+    lineHeight: 22,
+  },
+  featureList: {
+    backgroundColor: '#FFFFFF',
+    borderRadius: 16,
+    padding: 20,
+    width: '100%',
+  },
+  featureTitle: {
+    fontSize: 16,
+    fontWeight: 'bold',
+    color: KurdistanColors.kesk,
+    marginBottom: 12,
+  },
+  featureItem: {
+    fontSize: 14,
+    color: '#555',
+    marginBottom: 8,
+    lineHeight: 20,
+  },
+});
+
+export default VPNScreen;