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BREAKING app package, database, and URLs are no longer valid

src/screens/profile/SettingsScreen.tsx

@@ -1,6 +1,6 @@
-/**
+/**
  * 设置页 SettingsScreen（响应式适配）
- * 胡萝卜BBS - 应用设置
+ * 威友 - 应用设置
  * 在宽屏下居中显示，最大宽度限制
  */
 
@@ -363,7 +363,7 @@ export const SettingsScreen: React.FC = () => {
 
       <View style={styles.footer}>
         <Text variant="caption" color={colors.text.hint}>
-          萝卜社区 v{APP_VERSION}
+          威友 v{APP_VERSION}
         </Text>
         <Text variant="caption" color={colors.text.hint} style={styles.copyright}>
           © 2026 青春之旅电子信息科技（威海）有限公司