集成 Timber 日志框架，降级 AGP/Gradle 适配 JDK 17，修复构建设置

- 新增 PosefitApplication 初始化 Timber DebugTree

- WebRtcSenderClient/MainActivity/SimpleSdpObserver 添加 Timber 日志

- AGP 9.2.1 → 8.7.3，Gradle 9.4.1 → 8.11.1 适配 JDK 17

- compileSdk/targetSdk 恢复为 34，minSdk 保持 29 支持 Android 10

- 添加 android.useAndroidX=true 修复构建检查

- 删除 gradle-daemon-jvm.properties (JDK 21 残留配置)

- 信令端口默认改为 8765

gradle.properties

@@ -7,6 +7,8 @@
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+org.gradle.java.home=C\:\\Program Files\\Java\\jdk-17
+android.useAndroidX=true
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. For more details, visit
 # https://developer.android.com/r/tools/gradle-multi-project-decoupled-projects