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BREAKING app package, database, and URLs are no longer valid

package.json

@@ -1,6 +1,6 @@
 {
-  "name": "carrot_bbs",
-  "version": "1.0.3",
+  "name": "with_you",
+  "version": "0.1.sha",
   "main": "expo-router/entry",
   "scripts": {
     "start": "expo start",