feat: Flutter APK 编译成功 + Gradle 配置修复 + APK 下载部署 + 待优化清单

- 通过 qemu-user-static 实现 ARM64 主机编译 Android APK (51MB)
- 修复 Gradle: Aliyun 镜像 + PREFER_SETTINGS + JVM 内存 1536M
- 部署 APK 到 configs/downloads/, Web 下载接口已验证 (HTTP 200)
- 新增 Flutter TODO.md: 10项待优化 (P0/P1/P2 分级)
- 新增 pm_soul.md, 更新 routes.rs APK 下载路由

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clients/flutter/android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-all.zip