fix(channels): support kimi/zhipu/deepseek platforms in channel pricing

- ChannelsView platformOrder now includes the three CN provider
  platforms so channel pricing can be configured for them; composite
  group expansion/attachment stays limited to the five main platforms
  (matches backend isConcreteRequestPlatform and composite-routes
  target_platform validation)
- SyncPricingModels maps kimi->moonshot, zhipu->zhipu,
  deepseek->deepseek; also fixes gemini mapping to "google" which
  matched zero catalog entries (provider key is "gemini")
- Add CN platform colors to channel pricing model tag classes

frontend/src/components/admin/channel/types.ts

@@ -368,6 +368,9 @@ export function getPlatformTagClass(platform: string): string {
     case 'gemini': return 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400'
     case 'antigravity': return 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-400'
     case 'grok': return 'bg-slate-100 text-slate-700 dark:bg-slate-800 dark:text-slate-300'
+    case 'kimi': return 'bg-pink-100 text-pink-700 dark:bg-pink-900/30 dark:text-pink-400'
+    case 'zhipu': return 'bg-indigo-100 text-indigo-700 dark:bg-indigo-900/30 dark:text-indigo-400'
+    case 'deepseek': return 'bg-teal-100 text-teal-700 dark:bg-teal-900/30 dark:text-teal-400'
     default: return 'bg-gray-100 text-gray-700 dark:bg-gray-900/30 dark:text-gray-400'
   }
 }
@@ -380,6 +383,9 @@ export function getPlatformTextClass(platform: string): string {
     case 'gemini': return 'text-blue-700 dark:text-blue-400'
     case 'antigravity': return 'text-purple-700 dark:text-purple-400'
     case 'grok': return 'text-slate-700 dark:text-slate-300'
+    case 'kimi': return 'text-pink-700 dark:text-pink-400'
+    case 'zhipu': return 'text-indigo-700 dark:text-indigo-400'
+    case 'deepseek': return 'text-teal-700 dark:text-teal-400'
     default: return ''
   }
 }