feat(analytics): add daily trend and activity heatmap endpoints, and implement corresponding frontend components

- Added new API endpoints for daily trend data and activity heatmap in analyticsRoutes.ts.
- Created new frontend components: ActivityChart, ControlBar, Heatmap, SummaryCards, TopicList, TrendChart, UserTable, and ViolatorTable for displaying analytics data.
- Implemented loading and empty states in the new components.
- Enhanced the existing moderation tests with remote fallback handling for Indonesian text normalization.

frontend/src/api/analytics.ts

@@ -139,3 +139,47 @@ export async function fetchViolators(params: {
   });
   return request<ViolatorStat[]>(`/api/analytics/violators?${searchParams}`);
 }
+
+export interface TrendBucket {
+  date: string;
+  count: number;
+  clean: number;
+  warned: number;
+  flagged: number;
+  error: number;
+}
+
+export interface HeatmapCell {
+  dayOfWeek: number;
+  hour: number;
+  count: number;
+  clean: number;
+  warned: number;
+  flagged: number;
+}
+
+export async function fetchTrend(params: {
+  guildId: string;
+  channelId?: string;
+  hours?: number;
+}): Promise<TrendBucket[]> {
+  const searchParams = new URLSearchParams({
+    guildId: params.guildId,
+    ...(params.channelId && { channelId: params.channelId }),
+    ...(params.hours && { hours: String(params.hours) }),
+  });
+  return request<TrendBucket[]>(`/api/analytics/trend?${searchParams}`);
+}
+
+export async function fetchHeatmap(params: {
+  guildId: string;
+  channelId?: string;
+  hours?: number;
+}): Promise<HeatmapCell[]> {
+  const searchParams = new URLSearchParams({
+    guildId: params.guildId,
+    ...(params.channelId && { channelId: params.channelId }),
+    ...(params.hours && { hours: String(params.hours) }),
+  });
+  return request<HeatmapCell[]>(`/api/analytics/heatmap?${searchParams}`);
+}