refactor(monitoring): simplify brand dashboard and harden citation rendering

- drop brand_time_buckets and sparkline/coverage UI; dashboard now returns a single day
- compute mention rate from total actual samples instead of averaging per-platform rates
- canonicalize ai_platform_id across services and aggregate platform-overview snapshots
- strip mojibake and non-answer noise from callback payloads and question detail answers
- keep Kimi citations panel-only; still store raw search_results for audit
- render linked [n] inline citations for qwen/yuanbao answers with scroll-to-source behavior
- restrict立即采集 to today's business date with a clear i18n hint
- refresh content-citations into an ant-design table with truncation and hover styling

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

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

@@ -0,0 +1,22 @@
+import { aiPlatformCatalog } from "@geo/shared-types";
+
+const monitoringPlatformIds = new Set(aiPlatformCatalog.map((item) => item.id));
+
+export function normalizeMonitoringPlatformId(platformId?: string | null): string {
+  return String(platformId ?? "").trim().toLowerCase();
+}
+
+export function isMonitoringPlatformId(platformId?: string | null): boolean {
+  const normalized = normalizeMonitoringPlatformId(platformId);
+  return Boolean(normalized) && monitoringPlatformIds.has(normalized);
+}
+
+export function normalizeMonitoringPlatformFilter(value: unknown): string {
+  const normalized = normalizeMonitoringPlatformId(
+    String(Array.isArray(value) ? value[0] ?? "" : value ?? ""),
+  );
+  if (!normalized) {
+    return "all";
+  }
+  return monitoringPlatformIds.has(normalized) ? normalized : "all";
+}