Rebrand the entire application from "胡萝卜社区" (Carrot BBS) to "威友" (WithYou), including:

- Update app name, package name (skin.carrot.bbs → cn.qczlit.withyou), and bundle identifier
- Update API endpoints (bbs.littlelan.cn → withyou.littlelan.cn)
- Update URL scheme (carrotbbs:// → withyou://)
- Rename database from carrot_bbs to with_you
- Update CI/CD pipeline image names and artifact naming
- Add Android signing configuration for release builds
- Update all UI text and comments throughout the codebase
- Refactor registerStore to use in-memory state instead of AsyncStorage persistence
- Improve WebRTC track handling and call stream management
- Add metro platform resolution for native platform support

BREAKING app package, database, and URLs are no longer valid

plugins/withForegroundService.js

@@ -1,4 +1,4 @@
-const { withAndroidManifest, withDangerousMod } = require('@expo/config-plugins');
+const { withAndroidManifest, withDangerousMod } = require('@expo/config-plugins');
 const fs = require('fs');
 const path = require('path');
 
@@ -18,10 +18,10 @@ const FOREGROUND_SERVICE_DATA_SYNC = 'android.permission.FOREGROUND_SERVICE_DATA
  */
 const withForegroundService = (config, options = {}) => {
   const {
-    notificationTitle = '萝卜社区',
+    notificationTitle = '威友',
     notificationBody = '正在后台同步消息',
     notificationIcon = 'ic_notification',
-    channelId = 'carrot_sync_foreground',
+    channelId = 'withyou_sync_foreground',
     channelName = '消息同步',
   } = options;