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/services/messageService.ts

@@ -22,14 +22,7 @@ import {
   CursorPaginationRequest,
   CursorPaginationResponse,
 } from '../types/dto';
-import {
-  getConversationCache,
-  getConversationListCache,
-  saveConversationCache,
-  saveConversationsWithRelatedCache,
-  updateConversationCacheUnreadCount,
-  saveUsersCache,
-} from './database';
+import { conversationRepository, userCacheRepository } from '@/database';
 
 /** 远端会话列表分页（offset / cursor）统一结果：拉取成功后均已执行本地缓存同步 */
 export interface RemoteConversationListPageResult {
@@ -55,7 +48,7 @@ class MessageService {
     const groups = list
       .map(conv => conv.group)
       .filter((group): group is NonNullable<typeof group> => Boolean(group));
-    await saveConversationsWithRelatedCache(list, users, groups);
+    await conversationRepository.saveWithRelated(list, users, groups);
   }
 
   /** offset 会话列表单页：请求 + 落库 */
@@ -152,12 +145,12 @@ class MessageService {
     const response = await api.get<ConversationDetailResponse>(
       `/conversations/${encodeURIComponent(id)}`
     );
-    await saveConversationCache(response.data);
+    await conversationRepository.saveCache(response.data);
     if (response.data.participants?.length) {
-      await saveUsersCache(response.data.participants);
+      await userCacheRepository.saveBatch(response.data.participants);
     }
     if (response.data.last_message?.sender) {
-      await saveUsersCache([response.data.last_message.sender]);
+      await userCacheRepository.save(response.data.last_message.sender);
     }
     return response.data;
   }
@@ -195,7 +188,7 @@ class MessageService {
   ): Promise<ConversationListResponse> {
     // 如果强制刷新,直接从服务器获取,不使用缓存
     if (!forceRefresh) {
-      const cachedList = await getConversationListCache();
+      const cachedList = await conversationRepository.getListCache();
       if (cachedList.length > 0) {
         // 后台刷新数据,但不阻塞当前返回
         this.refreshConversationsFromServer(page, pageSize).catch(error => {
@@ -235,9 +228,9 @@ class MessageService {
     const response = await api.post<ConversationResponse>('/conversations', {
       user_id: userId,
     });
-    await saveConversationCache(response.data);
+    await conversationRepository.saveCache(response.data);
     if (response.data.participants?.length) {
-      await saveUsersCache(response.data.participants);
+      await userCacheRepository.saveBatch(response.data.participants);
     }
     return response.data;
   }
@@ -247,7 +240,7 @@ class MessageService {
    * GET /api/v1/conversations/:id
    */
   async getConversationById(id: string): Promise<ConversationDetailResponse> {
-    const cached = await getConversationCache(id);
+    const cached = await conversationRepository.getCache(id);
     if (cached) {
       this.refreshConversationDetailFromServer(id).catch(error => {
         console.error('后台刷新会话详情失败:', error);
@@ -564,7 +557,7 @@ class MessageService {
       last_read_seq: Number(seq),
     });
     // 立即清零本地缓存中的 unread_count，并写入已读游标，避免冷启动仍显示旧红点
-    updateConversationCacheUnreadCount(conversationId, 0, Number(seq)).catch(error => {
+    conversationRepository.updateCacheUnreadCount(conversationId, 0, Number(seq)).catch(error => {
       console.error('更新本地会话未读数失败:', error);
     });
   }