feat: support Grok platform account imports

frontend/src/views/Websites.vue

@@ -617,6 +617,7 @@
                 <el-option label="OpenAI 兼容" value="openai" />
                 <el-option label="Anthropic" value="anthropic" />
                 <el-option label="Gemini" value="gemini" />
+                <el-option label="Grok" value="grok" />
                 <el-option label="Antigravity" value="antigravity" />
               </el-select>
             </el-form-item>
@@ -2339,6 +2340,7 @@ function detectPlatform(item: { group_name?: string; group_id?: string; key_name
   const text = `${item.group_name || ''} ${item.group_id || ''} ${item.key_name || ''}`.toLowerCase()
   if (text.includes('claude') || text.includes('anthropic')) return 'Anthropic'
   if (text.includes('gemini')) return 'Gemini'
+  if (text.includes('grok') || text.includes('xai')) return 'Grok'
   if (text.includes('antigravity')) return 'Antigravity'
   return 'OpenAI 兼容'
 }
@@ -2348,6 +2350,7 @@ function platformLabel(platform: string) {
     openai: 'OpenAI 兼容',
     anthropic: 'Anthropic',
     gemini: 'Gemini',
+    grok: 'Grok',
     antigravity: 'Antigravity',
   }
   return map[platform] || platform || '—'