feat(Theme): enhance theming and UI consistency across components

- Updated app.json to set userInterfaceStyle to automatic for improved theme adaptability.
- Refactored layout components to utilize useAppColors for dynamic theming, ensuring consistent color usage.
- Introduced SystemChrome component to manage system UI background color based on theme.
- Enhanced TabsLayout, ProfileStackLayout, and other components to leverage new theming structure.
- Improved QRCodeScanner, SearchBar, and CommentItem styles to align with the updated theme system.
- Consolidated styles in SystemMessageItem and TabBar for better maintainability and visual coherence.

src/components/common/SearchBar.tsx

@@ -0,0 +1,137 @@
+/**
+ * SearchBar 搜索栏组件
+ * 用于搜索内容
+ */
+
+import React, { useMemo, useState } from 'react';
+import { View, TextInput, TouchableOpacity, StyleSheet } from 'react-native';
+import { MaterialCommunityIcons } from '@expo/vector-icons';
+import { spacing, fontSizes, borderRadius, useAppColors, type AppColors } from '../../theme';
+
+interface SearchBarProps {
+  value: string;
+  onChangeText: (text: string) => void;
+  onSubmit: () => void;
+  placeholder?: string;
+  onFocus?: () => void;
+  onBlur?: () => void;
+  autoFocus?: boolean;
+}
+
+function createSearchBarStyles(colors: AppColors) {
+  return StyleSheet.create({
+    container: {
+      flexDirection: 'row',
+      alignItems: 'center',
+      backgroundColor: colors.background.paper,
+      borderRadius: borderRadius.full,
+      paddingHorizontal: spacing.xs,
+      height: 46,
+      borderWidth: 1,
+      borderColor: colors.divider,
+      shadowColor: 'transparent',
+      shadowOffset: { width: 0, height: 0 },
+      shadowOpacity: 0,
+      shadowRadius: 0,
+      elevation: 0,
+    },
+    containerFocused: {
+      borderColor: colors.primary.main,
+      shadowColor: 'transparent',
+      shadowOffset: { width: 0, height: 0 },
+      shadowOpacity: 0,
+      shadowRadius: 0,
+      elevation: 0,
+    },
+    searchIconWrap: {
+      width: 30,
+      height: 30,
+      marginLeft: spacing.xs,
+      marginRight: spacing.xs,
+      borderRadius: borderRadius.full,
+      backgroundColor: `${colors.text.secondary}12`,
+      alignItems: 'center',
+      justifyContent: 'center',
+    },
+    searchIconWrapFocused: {
+      backgroundColor: `${colors.primary.main}1A`,
+    },
+    input: {
+      flex: 1,
+      fontSize: fontSizes.md,
+      color: colors.text.primary,
+      paddingVertical: spacing.sm + 1,
+      paddingHorizontal: spacing.xs,
+    },
+    clearButton: {
+      width: 24,
+      height: 24,
+      marginHorizontal: spacing.xs,
+      borderRadius: borderRadius.full,
+      backgroundColor: `${colors.text.secondary}14`,
+      alignItems: 'center',
+      justifyContent: 'center',
+    },
+  });
+}
+
+const SearchBar: React.FC<SearchBarProps> = ({
+  value,
+  onChangeText,
+  onSubmit,
+  placeholder = '搜索...',
+  onFocus,
+  onBlur,
+  autoFocus = false,
+}) => {
+  const colors = useAppColors();
+  const styles = useMemo(() => createSearchBarStyles(colors), [colors]);
+  const [isFocused, setIsFocused] = useState(false);
+
+  const handleFocus = () => {
+    setIsFocused(true);
+    onFocus?.();
+  };
+
+  const handleBlur = () => {
+    setIsFocused(false);
+    onBlur?.();
+  };
+
+  return (
+    <View style={[styles.container, isFocused && styles.containerFocused]}>
+      <View style={[styles.searchIconWrap, isFocused && styles.searchIconWrapFocused]}>
+        <MaterialCommunityIcons
+          name="magnify"
+          size={18}
+          color={isFocused ? colors.primary.main : colors.text.secondary}
+        />
+      </View>
+      <TextInput
+        style={styles.input}
+        value={value}
+        onChangeText={onChangeText}
+        placeholder={placeholder}
+        placeholderTextColor={colors.text.hint}
+        returnKeyType="search"
+        onSubmitEditing={onSubmit}
+        onFocus={handleFocus}
+        onBlur={handleBlur}
+        autoFocus={autoFocus}
+        cursorColor={colors.primary.main}
+        selectionColor={`${colors.primary.main}40`}
+      />
+      {value.length > 0 && (
+        <TouchableOpacity
+          onPress={() => onChangeText('')}
+          style={styles.clearButton}
+          activeOpacity={0.7}
+        >
+          <MaterialCommunityIcons name="close" size={14} color={colors.text.secondary} />
+        </TouchableOpacity>
+      )}
+    </View>
+  );
+};
+
+export default SearchBar;