feat(client/ios): 补齐 App 图标(iPhone+iPad 全尺寸,去 alpha)

iOS AppIcon.appiconset 只有 Contents.json、无任何 PNG → 桌面图标空白。
以 design 单源 assets/app-icon.svg(去圆角 rx=0 全幅方形)经 qlmanage 渲染 1024,
flutter_launcher_icons 铺开 21 张全尺寸(含 iPad 76/83.5)并去 alpha(App Store 合规)。
新增 dev_dep flutter_launcher_icons + 配置块,改图标重渲源图后 dart run 即可。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/pubspec.yaml

@@ -27,6 +27,16 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
   flutter_lints: ^4.0.0
+  flutter_launcher_icons: ^0.14.1
+
+# ── App 图标生成(flutter_launcher_icons)──
+# 源图 assets/app-icon-ios-1024.png = design 单源 assets/app-icon.svg 去掉圆角(rx=0,全幅
+# 方形,iOS 自行加圆角)、qlmanage 渲染 1024 而来。改图标:重渲源图后跑
+# `dart run flutter_launcher_icons`(自动铺 iPhone+iPad 全尺寸、去 alpha、重写 Contents.json)。
+flutter_launcher_icons:
+  ios: true
+  remove_alpha_ios: true
+  image_path: "assets/app-icon-ios-1024.png"
 
 # lucide_icons-0.257.0 defines LucideIconData extends IconData, which breaks
 # when Flutter SDK marks IconData as final. Override with a local patched copy