feat: add analytics hooks and routes for moderation statistics

- Implemented `useAnalytics` hook for fetching and managing analytics data.
- Created `analyticsStore.ts` to handle database queries for hourly stats, topic trends, user leaderboard, and moderation stats.
- Added Express routes for analytics endpoints including overview, hourly stats, topic trends, user leaderboard, moderation stats, and top violators.
- Introduced a utility function `filterHits` for filtering specific terms in text.

frontend/src/types/ui.ts

@@ -1,4 +1,4 @@
-export type DashboardTab = "voice" | "media" | "messages" | "review" | "recordings";
+export type DashboardTab = "voice" | "media" | "messages" | "review" | "recordings" | "analytics";
 
 export interface UIState {
   selectedGuild?: string;