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BREAKING app package, database, and URLs are no longer valid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/auth/RegisterScreen.tsx

@@ -1,13 +1,13 @@
-/**
+/**
  * 注册页面（分步向导版）
- * 胡萝卜BBS - 用户注册流程
+ * 威友 - 用户注册流程
  * 
  * 步骤：
  * 1. 输入邮箱
  * 2. 填写验证码
  * 3. 设置用户信息
  * 
- * 使用 registerStore 持久化存储步骤数据
+ * 使用 registerStore 纯内存状态管理
  */
 
 import React, { useEffect, useMemo, useRef } from 'react';
@@ -42,7 +42,7 @@ import { RegisterStep1Email } from './RegisterStep1Email';
 import { RegisterStep2Verification } from './RegisterStep2Verification';
 import { RegisterStep3Profile } from './RegisterStep3Profile';
 
-// 胡萝卜橙主题色
+// 威友橙主题色
 const THEME_COLORS = {
   primary: '#FF6B35',
   primaryLight: '#FF8C5A',
@@ -87,16 +87,9 @@ export const RegisterScreen: React.FC = () => {
   const fadeAnim = useRef(new Animated.Value(0)).current;
   const slideAnim = useRef(new Animated.Value(20)).current;
 
-  // 恢复持久化的数据
-  const [isHydrated, setIsHydrated] = React.useState(false);
-
+  // 页面挂载时重置倒计时，避免上次残留的倒计时导致无法重新获取验证码
   useEffect(() => {
-    const hydrateData = async () => {
-      const { hydrate } = useRegisterStore.getState();
-      await hydrate();
-      setIsHydrated(true);
-    };
-    hydrateData();
+    setCountdown(0);
   }, []);
 
   // 检查是否已登录