feat(auth): implement multi-step registration process and enhance background services

- Updated RegisterScreen to support a multi-step registration flow with components for email input, verification, and profile setup.
- Added new components: VerificationCodeInput, StepIndicator, and corresponding types for step management.
- Enhanced background service to check authentication status before executing tasks, improving app reliability.
- Updated TypeScript configuration to include module resolution and JSON module support.

This update significantly improves the user registration experience and ensures background tasks are only executed for authenticated users.

src/screens/auth/RegisterStep1Email.tsx

@@ -0,0 +1,192 @@
+/**
+ * 注册步骤1：输入邮箱
+ * 包含邮箱输入框和获取验证码按钮
+ */
+
+import React, { useState } from 'react';
+import {
+  View,
+  Text,
+  StyleSheet,
+  TextInput,
+  TouchableOpacity,
+} from 'react-native';
+import { MaterialCommunityIcons } from '@expo/vector-icons';
+import { useAppColors, type AppColors } from '../../theme';
+import { RegisterStepProps } from './types';
+
+const THEME_COLORS = {
+  primary: '#FF6B35',
+  primaryLight: '#FF8C5A',
+  primaryDark: '#E55A2B',
+};
+
+export const RegisterStep1Email: React.FC<RegisterStepProps> = ({
+  formData,
+  updateFormData,
+  onNext,
+  colors: propColors,
+  sendingCode,
+  countdown,
+  onSendCode,
+}) => {
+  const colors = propColors || useAppColors();
+  const styles = createStyles(colors);
+
+  const [emailError, setEmailError] = useState('');
+
+  const validateEmail = (email: string): boolean => {
+    if (!email.trim()) {
+      setEmailError('请输入邮箱');
+      return false;
+    }
+    if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email)) {
+      setEmailError('请输入正确的邮箱地址');
+      return false;
+    }
+    setEmailError('');
+    return true;
+  };
+
+  const handleSendCode = async () => {
+    if (!validateEmail(formData.email)) {
+      return;
+    }
+    if (onSendCode) {
+      const success = await onSendCode(formData.email);
+      if (success) {
+        onNext();
+      }
+    }
+  };
+
+  return (
+    <View style={styles.container}>
+      <View style={styles.formSection}>
+        {/* 邮箱输入框 */}
+        <View style={styles.inputContainer}>
+          <Text style={styles.inputLabel}>邮箱</Text>
+          <View
+            style={[
+              styles.inputWrapper,
+              emailError ? styles.inputWrapperError : null,
+            ]}
+          >
+            <TextInput
+              style={styles.input}
+              placeholder="请输入邮箱地址"
+              placeholderTextColor={colors.text?.hint || '#999'}
+              value={formData.email}
+              onChangeText={(text) => {
+                updateFormData({ email: text });
+                if (emailError) setEmailError('');
+              }}
+              autoCapitalize="none"
+              autoCorrect={false}
+              keyboardType="email-address"
+              editable={!sendingCode}
+            />
+            {formData.email.length > 0 &&
+              /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(formData.email) && (
+                <MaterialCommunityIcons
+                  name="check-circle"
+                  size={20}
+                  color={THEME_COLORS.primary}
+                  style={styles.checkIcon}
+                />
+              )}
+          </View>
+          {emailError ? (
+            <Text style={styles.errorText}>{emailError}</Text>
+          ) : null}
+        </View>
+
+        {/* 获取验证码按钮 */}
+        <TouchableOpacity
+          style={[
+            styles.actionButton,
+            (sendingCode || countdown > 0) && styles.actionButtonDisabled,
+          ]}
+          onPress={handleSendCode}
+          disabled={sendingCode || countdown > 0}
+          activeOpacity={0.9}
+        >
+          <Text style={styles.actionButtonText}>
+            {sendingCode
+              ? '发送中...'
+              : countdown > 0
+              ? `${countdown}秒后重试`
+              : '获取验证码'}
+          </Text>
+        </TouchableOpacity>
+      </View>
+    </View>
+  );
+}
+
+function createStyles(colors: AppColors) {
+  return StyleSheet.create({
+    container: {
+      flex: 1,
+      paddingTop: 20,
+    },
+    formSection: {
+      marginBottom: 24,
+    },
+    inputContainer: {
+      marginBottom: 24,
+    },
+    inputLabel: {
+      fontSize: 14,
+      fontWeight: '500',
+      color: colors.text?.secondary || '#666',
+      marginBottom: 10,
+    },
+    inputWrapper: {
+      flexDirection: 'row',
+      alignItems: 'center',
+      backgroundColor: '#F5F5F7',
+      borderRadius: 14,
+      paddingHorizontal: 18,
+      height: 56,
+      borderWidth: 1,
+      borderColor: 'transparent',
+    },
+    inputWrapperError: {
+      borderColor: colors.error?.main || '#FF4444',
+    },
+    input: {
+      flex: 1,
+      fontSize: 16,
+      color: colors.text?.primary || '#333',
+      height: 56,
+    },
+    checkIcon: {
+      marginLeft: 8,
+    },
+    errorText: {
+      fontSize: 12,
+      color: colors.error?.main || '#FF4444',
+      marginTop: 6,
+      marginLeft: 4,
+    },
+    actionButton: {
+      height: 56,
+      borderRadius: 14,
+      backgroundColor: '#FF6B35',
+      alignItems: 'center',
+      justifyContent: 'center',
+      marginTop: 8,
+    },
+    actionButtonDisabled: {
+      opacity: 0.6,
+    },
+    actionButtonText: {
+      fontSize: 17,
+      fontWeight: '600',
+      color: '#FFFFFF',
+    },
+  });
+}
+
+export default RegisterStep1Email;