feat: Expo scaffold + auth screens + core screens (#39-#46, #48)

components/AppInput.tsx

@@ -0,0 +1,48 @@
+import React, { useState } from 'react';
+import { View, TextInput, Text, TouchableOpacity, TextInputProps } from 'react-native';
+
+interface AppInputProps extends TextInputProps {
+  label?: string;
+  error?: string;
+  secureToggle?: boolean;
+  leftIcon?: React.ReactNode;
+}
+
+export const AppInput: React.FC<AppInputProps> = ({
+  label,
+  error,
+  secureToggle,
+  leftIcon,
+  ...props
+}) => {
+  const [showPassword, setShowPassword] = useState(false);
+
+  return (
+    <View className="mb-4">
+      {label && (
+        <Text className="text-sm font-medium text-gray-700 mb-1.5">{label}</Text>
+      )}
+      <View
+        className={`flex-row items-center bg-white border rounded-xl px-4 h-12 ${
+          error ? 'border-red-500' : 'border-gray-200'
+        }`}
+      >
+        {leftIcon && <View className="mr-2">{leftIcon}</View>}
+        <TextInput
+          className="flex-1 text-gray-900 text-base"
+          placeholderTextColor="#9CA3AF"
+          secureTextEntry={secureToggle ? !showPassword : props.secureTextEntry}
+          {...props}
+        />
+        {secureToggle && (
+          <TouchableOpacity onPress={() => setShowPassword(!showPassword)}>
+            <Text className="text-blue-600 text-sm font-medium">
+              {showPassword ? 'Hide' : 'Show'}
+            </Text>
+          </TouchableOpacity>
+        )}
+      </View>
+      {error && <Text className="text-red-500 text-xs mt-1">{error}</Text>}
+    </View>
+  );
+};