feat: 集成离线数字货币SVG图标系统

- 下载16个主流币种SVG图标(BTC/ETH/USDT/BNB/SOL/XRP/ADA/DOGE/DOT/MATIC/SHIB/LTC/AVAX/LINK/UNI/ATOM)
- 图标来源: spothq/cryptocurrency-icons (开源)
- 更新CoinIcon组件使用flutter_svg加载SVG格式
- 添加flutter_svg依赖
- 构建验证通过

flutter_monisuo/pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  args:
+    dependency: transitive
+    description:
+      name: args
+      sha256: d0481093c50b1da8910eb0bb301626d4d8eb7284aa739614d2b394ee09e3ea04
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.7.0"
   async:
     dependency: transitive
     description:
@@ -203,6 +211,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.1.3"
+  flutter_svg:
+    dependency: "direct main"
+    description:
+      name: flutter_svg
+      sha256: "1ded017b39c8e15c8948ea855070a5ff8ff8b3d5e83f3446e02d6bb12add7ad9"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.4"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -437,6 +453,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.9.1"
+  path_parsing:
+    dependency: transitive
+    description:
+      name: path_parsing
+      sha256: "883402936929eac138ee0a45da5b0f2c80f89913e6dc3bf77eb65b84b409c6ca"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.0"
   path_provider:
     dependency: transitive
     description:
@@ -485,6 +509,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.3.0"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: "91bd59303e9f769f108f8df05e371341b15d59e995e6806aefab827b58336675"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.2"
   platform:
     dependency: transitive
     description:
@@ -642,6 +674,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  vector_graphics:
+    dependency: transitive
+    description:
+      name: vector_graphics
+      sha256: "81da85e9ca8885ade47f9685b953cb098970d11be4821ac765580a6607ea4373"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.21"
+  vector_graphics_codec:
+    dependency: transitive
+    description:
+      name: vector_graphics_codec
+      sha256: "99fd9fbd34d9f9a32efd7b6a6aae14125d8237b10403b422a6a6dfeac2806146"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.13"
+  vector_graphics_compiler:
+    dependency: transitive
+    description:
+      name: vector_graphics_compiler
+      sha256: "5a88dd14c0954a5398af544651c7fb51b457a2a556949bfb25369b210ef73a74"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.0"
   vector_math:
     dependency: transitive
     description:
@@ -674,6 +730,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.0"
+  xml:
+    dependency: transitive
+    description:
+      name: xml
+      sha256: "971043b3a0d3da28727e40ed3e0b5d18b742fa5a68665cca88e74b7876d5e025"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.6.1"
   yaml:
     dependency: transitive
     description: