refactor(database): migrate to new modular database layer and unify data access

- Remove legacy database.ts, LocalDataSource.ts, and MessageRepository.ts
- Create new src/database/ module with messageRepository, userCacheRepository, conversationRepository, and groupCacheRepository
- Update all consumers to import from @/database instead of services/database
- Add web platform blur handling for modal components to fix focus issues
- Flatten SystemMessageItem and NotificationsScreen styles for consistent design
- Add draggable slider in ChatSettingsScreen and dynamic font size support
- Introduce 9 new chat color themes
- Add profile screens for about, terms, and privacy policy with navigation routes
- Add policy links to login and registration screens
- Fix post share URL format from /posts/ to /post/

src/screens/message/components/ChatScreen/EmojiPanel.tsx

@@ -5,7 +5,7 @@
  */
 
 import React, { useState, useEffect, useCallback, useMemo } from 'react';
-import { View, TouchableOpacity, ActivityIndicator, Modal, Alert, Dimensions, StyleSheet, FlatList, ListRenderItem, ScrollView } from 'react-native';
+import { View, TouchableOpacity, ActivityIndicator, Modal, Alert, Dimensions, StyleSheet, FlatList, ListRenderItem, ScrollView, Platform } from 'react-native';
 import { Image as ExpoImage } from 'expo-image';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
 import * as ImagePicker from 'expo-image-picker';
@@ -18,6 +18,12 @@ import { useAppColors, spacing } from '../../../../theme';
 
 const { height: SCREEN_HEIGHT } = Dimensions.get('window');
 
+const blurActiveElementOnWeb = () => {
+  if (Platform.OS !== 'web') return;
+  const active = (globalThis as any)?.document?.activeElement as { blur?: () => void } | undefined;
+  active?.blur?.();
+};
+
 // 表情尺寸配置 - 固定宽度 40px，使用 flex 布局
 const EMOJI_SIZES = {
   mobile: { size: 24, itemWidth: 40, itemHeight: 40 },
@@ -176,6 +182,7 @@ export const EmojiPanel: React.FC<EmojiPanelProps> = ({
 
   // 打开管理界面
   const handleOpenManage = () => {
+    blurActiveElementOnWeb();
     setShowManageModal(true);
     setManageMode(false);
     setSelectedStickers(new Set());

src/screens/message/components/ChatScreen/SegmentRenderer.tsx

@@ -33,6 +33,7 @@ import {
 } from '../../../../types/dto';
 import { spacing, useAppColors, type AppColors } from '../../../../theme';
 import { SenderInfo } from './types';
+import { useChatSettingsStore } from '../../../../stores/chatSettingsStore';
 
 const IMAGE_MAX_WIDTH = 200;
 const IMAGE_MAX_HEIGHT = 260;
@@ -617,7 +618,8 @@ export const ReplyPreviewSegment: React.FC<ReplyPreviewSegmentProps> = ({
   getSenderInfo,
 }) => {
   const themeColors = useAppColors();
-  const styles = useMemo(() => createSegmentStyles(themeColors), [themeColors]);
+  const fontSize = useChatSettingsStore((s) => s.fontSize);
+  const styles = useMemo(() => createSegmentStyles(themeColors, fontSize), [themeColors, fontSize]);
 
   if (!replyMessage) {
     // 如果没有引用消息详情，只显示引用ID
@@ -729,7 +731,8 @@ export const MessageSegmentsRenderer: React.FC<{
   getSenderInfo,
 }) => {
   const themeColors = useAppColors();
-  const segStyles = useMemo(() => createSegmentStyles(themeColors), [themeColors]);
+  const fontSize = useChatSettingsStore((s) => s.fontSize);
+  const segStyles = useMemo(() => createSegmentStyles(themeColors, fontSize), [themeColors, fontSize]);
 
   const replySegment = segments.find(s => s.type === 'reply');
   const otherSegments = segments.filter(s => s.type !== 'reply');
@@ -815,7 +818,7 @@ const formatDuration = (seconds: number): string => {
   return mins > 0 ? `${mins}:${secs.toString().padStart(2, '0')}` : `0:${secs.toString().padStart(2, '0')}`;
 };
 
-function createSegmentStyles(colors: AppColors) {
+function createSegmentStyles(colors: AppColors, fontSize: number = 16) {
   return StyleSheet.create({
   // 容器
   segmentsContainer: {
@@ -847,10 +850,10 @@ function createSegmentStyles(colors: AppColors) {
     marginTop: 2,
   },
 
-  // 文本 - 适配暗色模式
+  // 文本 - 适配暗色模式，支持动态字号
   textContent: {
-    fontSize: 17.5,
-    lineHeight: 25,
+    fontSize,
+    lineHeight: Math.round(fontSize * 1.43),
     letterSpacing: 0.1,
     fontWeight: '400',
   },
@@ -861,10 +864,10 @@ function createSegmentStyles(colors: AppColors) {
     color: colors.chat.textPrimary,
   },
 
-  // @提及 - 微信/QQ 风格：更精致的高亮
+  // @提及 - 微信/QQ 风格：更精致的高亮，支持动态字号
   atText: {
-    fontSize: 16,
-    lineHeight: 22,
+    fontSize,
+    lineHeight: Math.round(fontSize * 1.4),
     fontWeight: '500',
   },
   atTextMe: {
@@ -904,7 +907,7 @@ function createSegmentStyles(colors: AppColors) {
     height: 28,
   },
   faceText: {
-    fontSize: 16,
+    fontSize,
     color: '#666',
   },
 
@@ -930,7 +933,7 @@ function createSegmentStyles(colors: AppColors) {
   },
   voiceDuration: {
     marginLeft: spacing.sm,
-    fontSize: 15,
+    fontSize: fontSize - 1,
     fontWeight: '500',
   },
 
@@ -1113,14 +1116,14 @@ function createSegmentStyles(colors: AppColors) {
     minWidth: 0,
   },
   replySender: {
-    fontSize: 13,
+    fontSize: fontSize - 3,
     fontWeight: '600',
     color: colors.chat.link,
     marginRight: 6,
     flexShrink: 0,
   },
   replyText: {
-    fontSize: 13,
+    fontSize: fontSize - 3,
     color: colors.chat.textTertiary,
     flex: 1,
     flexShrink: 1,

src/screens/message/components/ChatScreen/useChatScreen.ts

@@ -42,10 +42,7 @@ import {
   PendingChatAttachment,
 } from './types';
 import { TIME_SEPARATOR_INTERVAL, MEMBERS_PAGE_SIZE, MAX_PENDING_CHAT_IMAGES } from './constants';
-import {
-  deleteMessage as deleteMessageFromDb,
-  clearConversationMessages,
-} from '../../../../services/database';
+import { messageRepository } from '@/database';
 
 export const useChatScreen = () => {
   const getSendErrorMessage = useCallback((error: unknown, fallback: string) => {
@@ -1209,7 +1206,7 @@ export const useChatScreen = () => {
       const updatedMessages = messages.filter(m => m.id !== messageId);
       // 注意：这里我们依赖 MessageManager 的数据，所以需要通过其他方式刷新
       // 暂时只删除本地数据库
-      await deleteMessageFromDb(messageId);
+      await messageRepository.delete(messageId);
     } catch (error) {
       console.error('删除消息失败:', error);
       Alert.alert('删除失败', '无法删除消息');
@@ -1224,7 +1221,7 @@ export const useChatScreen = () => {
       setLastSeq(0);
       setFirstSeq(0);
       setHasMoreHistory(true);
-      await clearConversationMessages(conversationId);
+      await messageRepository.clearConversation(conversationId);
       // 刷新消息列表
       await refreshMessages();
     } catch (error) {