fix: 修复专属账号下拉框，仅显示dedicated类型账号

- 修改CreateApiKeyModal和EditApiKeyModal的过滤逻辑
- 专属账号下拉框只显示accountType='dedicated'的账号
- 移除accountType='group'的账号，这些账号通过分组调度
- 更新标签文字为'专属账号'以更准确描述

src/services/claudeAccountService.js

@@ -330,6 +330,7 @@ class ClaudeAccountService {
           errorMessage: account.errorMessage,
           accountType: account.accountType || 'shared', // 兼容旧数据，默认为共享
           priority: parseInt(account.priority) || 50, // 兼容旧数据，默认优先级50
+          platform: 'claude-oauth', // 添加平台标识，用于前端区分
           createdAt: account.createdAt,
           lastUsedAt: account.lastUsedAt,
           lastRefreshAt: account.lastRefreshAt,