优化配置，修复 demo bug

1，network 框架完善
2，websocket 机制完善
3，设计文档整理到架构文档
4，脚本，配置完善

apps/im_app/macos/Podfile

@@ -1,4 +1,4 @@
-platform :osx, '11.0'
+platform :osx, '14.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
@@ -38,5 +38,8 @@ end
 post_install do |installer|
   installer.pods_project.targets.each do |target|
     flutter_additional_macos_build_settings(target)
+    target.build_configurations.each do |config|
+      config.build_settings['SWIFT_VERSION'] ||= '6.2'
+    end
   end
 end