Merge PR #73: feat(antigravity): 添加 Antigravity (Cloud AI Companion) 平台支持

新增功能:
- Antigravity OAuth 授权流程支持
- Claude → Gemini 协议转换（Claude API 请求自动转换为 Gemini 格式）
- 配额刷新和状态显示
- 混合调度功能，支持 Anthropic 和 Antigravity 账户混合使用
- /antigravity 专用路由，支持仅使用 Antigravity 账户
- 前端 Antigravity 服务商标识和账户管理功能

冲突解决:
- CreateAccountModal.vue: 合并 data-tour 属性和 mixed-scheduling 属性
- EditAccountModal.vue: 合并 data-tour 属性和 mixed-scheduling 属性

代码质量改进:
- 修复 antigravity 类型文件的 gofmt 格式问题（struct 字段对齐、interface{} → any）
- 移除 .golangci.yml 中的 gofmt 排除规则
- 修复测试文件的格式问题

frontend/src/views/admin/AccountsView.vue

@@ -559,7 +559,8 @@ const platformOptions = computed(() => [
   { value: '', label: t('admin.accounts.allPlatforms') },
   { value: 'anthropic', label: t('admin.accounts.platforms.anthropic') },
   { value: 'openai', label: t('admin.accounts.platforms.openai') },
-  { value: 'gemini', label: t('admin.accounts.platforms.gemini') }
+  { value: 'gemini', label: t('admin.accounts.platforms.gemini') },
+  { value: 'antigravity', label: t('admin.accounts.platforms.antigravity') }
 ])
 
 const typeOptions = computed(() => [

frontend/src/views/admin/GroupsView.vue

@@ -82,11 +82,21 @@
                   ? 'bg-orange-100 text-orange-700 dark:bg-orange-900/30 dark:text-orange-400'
                   : value === 'openai'
                     ? 'bg-emerald-100 text-emerald-700 dark:bg-emerald-900/30 dark:text-emerald-400'
-                    : 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400'
+                    : value === 'antigravity'
+                      ? 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-400'
+                      : 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400'
               ]"
             >
               <PlatformIcon :platform="value" size="xs" />
-              {{ value === 'anthropic' ? 'Anthropic' : value === 'openai' ? 'OpenAI' : 'Gemini' }}
+              {{
+                value === 'anthropic'
+                  ? 'Anthropic'
+                  : value === 'openai'
+                    ? 'OpenAI'
+                    : value === 'antigravity'
+                      ? 'Antigravity'
+                      : 'Gemini'
+              }}
             </span>
           </template>
 
@@ -694,14 +704,16 @@ const exclusiveOptions = computed(() => [
 const platformOptions = computed(() => [
   { value: 'anthropic', label: 'Anthropic' },
   { value: 'openai', label: 'OpenAI' },
-  { value: 'gemini', label: 'Gemini' }
+  { value: 'gemini', label: 'Gemini' },
+  { value: 'antigravity', label: 'Antigravity' }
 ])
 
 const platformFilterOptions = computed(() => [
   { value: '', label: t('admin.groups.allPlatforms') },
   { value: 'anthropic', label: 'Anthropic' },
   { value: 'openai', label: 'OpenAI' },
-  { value: 'gemini', label: 'Gemini' }
+  { value: 'gemini', label: 'Gemini' },
+  { value: 'antigravity', label: 'Antigravity' }
 ])
 
 const editStatusOptions = computed(() => [