feat: SAPIENS Mobile App - Initial commit

React Native mobile application for SAPIENS news platform.
Consolidated all previous history into single commit.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

sapiense-ai-app/components/BottomTabBar.tsx

@@ -0,0 +1,107 @@
+import { View, Text, TouchableOpacity, StyleSheet } from 'react-native';
+import { Ionicons } from '@expo/vector-icons';
+
+interface BottomTabBarProps {
+  activeTab: 'people' | 'topics' | 'companies';
+  onTabChange: (tab: 'people' | 'topics' | 'companies') => void;
+  showBackButton?: boolean;
+  onBack?: () => void;
+}
+
+export default function BottomTabBar({ activeTab, onTabChange, showBackButton, onBack }: BottomTabBarProps) {
+  const tabs = [
+    { id: 'people' as const, label: 'People', icon: 'person-outline' as const },
+    { id: 'topics' as const, label: 'Topics', icon: 'newspaper-outline' as const },
+    { id: 'companies' as const, label: 'Companies', icon: 'business-outline' as const },
+  ];
+
+  return (
+    <View style={styles.container}>
+      {showBackButton && onBack ? (
+        <TouchableOpacity
+          style={styles.backTab}
+          onPress={onBack}
+          activeOpacity={0.7}
+        >
+          <Ionicons
+            name="arrow-back"
+            size={24}
+            color="#000"
+            style={styles.icon}
+          />
+          <Text style={styles.backLabel}>Back</Text>
+        </TouchableOpacity>
+      ) : null}
+      {tabs.map((tab) => (
+        <TouchableOpacity
+          key={tab.id}
+          style={[
+            styles.tab,
+            activeTab === tab.id && styles.activeTab,
+          ]}
+          onPress={() => onTabChange(tab.id)}
+          activeOpacity={0.7}
+        >
+          <Ionicons
+            name={tab.icon}
+            size={24}
+            color={activeTab === tab.id ? '#000' : '#666'}
+            style={styles.icon}
+          />
+          <Text
+            style={[
+              styles.label,
+              activeTab === tab.id && styles.activeLabel,
+            ]}
+          >
+            {tab.label}
+          </Text>
+        </TouchableOpacity>
+      ))}
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flexDirection: 'row',
+    backgroundColor: '#fff',
+    borderTopWidth: 1,
+    borderTopColor: '#e0e0e0',
+    paddingBottom: 8,
+    paddingTop: 8,
+  },
+  tab: {
+    flex: 1,
+    alignItems: 'center',
+    paddingVertical: 8,
+  },
+  activeTab: {
+    backgroundColor: '#f0f0f0',
+    borderRadius: 8,
+  },
+  icon: {
+    marginBottom: 4,
+  },
+  label: {
+    fontSize: 12,
+    color: '#666',
+  },
+  activeLabel: {
+    color: '#000',
+    fontWeight: '600',
+  },
+  backTab: {
+    flex: 1,
+    alignItems: 'center',
+    paddingVertical: 8,
+    backgroundColor: '#f0f0f0',
+    borderRadius: 8,
+    marginHorizontal: 4,
+  },
+  backLabel: {
+    fontSize: 12,
+    color: '#000',
+    fontWeight: '600',
+  },
+});