fix(accounts): hide AI-platform accounts from publish-only views

After splitting AI platforms into their own catalog, the admin MediaView and
desktop AccountsView still showed yuanbao/kimi/wenxin/deepseek/doubao/qwen
rows alongside publish platforms. Filter by publish catalog membership so
those views stay scoped to publish accounts only.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/admin-web/src/lib/publish-platforms.ts

@@ -25,6 +25,11 @@ const platformCatalog: Record<string, Omit<PublishPlatformOption, "accountLabel"
   dongchedi: { id: "dongchedi", name: "懂车帝", shortName: "懂", accent: "#fadb14" },
 };
 
+export function isPublishPlatformId(platformId?: string | null): boolean {
+  const normalized = normalizePublishPlatformId(platformId);
+  return Boolean(normalized) && normalized in platformCatalog;
+}
+
 export function getPublishPlatformMeta(platformId: string): Omit<PublishPlatformOption, "accountLabel" | "bound"> {
   const normalized = normalizePublishPlatformId(platformId);
   const fallbackShortName = normalized.slice(0, 1).toUpperCase() || "?";