feat: integrate real data into dashboard

- Created dashboard service with DB queries for users, economy, events
- Added client stats provider with 30s caching for Discord metrics
- Implemented /api/stats endpoint aggregating all dashboard data
- Created useDashboardStats React hook with auto-refresh
- Updated Dashboard.tsx to display real data with loading/error states
- Added comprehensive test coverage (11 tests passing)
- Replaced all mock values with live Discord and database metrics

bot/lib/clientStats.ts

@@ -0,0 +1,44 @@
+import { AuroraClient } from "./BotClient";
+import type { ClientStats } from "@shared/modules/dashboard/dashboard.types";
+
+// Cache for client stats (30 second TTL)
+let cachedStats: ClientStats | null = null;
+let lastFetchTime: number = 0;
+const CACHE_TTL_MS = 30 * 1000; // 30 seconds
+
+/**
+ * Get Discord client statistics with caching
+ * Respects rate limits by caching for 30 seconds
+ */
+export function getClientStats(): ClientStats {
+    const now = Date.now();
+
+    // Return cached stats if still valid
+    if (cachedStats && (now - lastFetchTime) < CACHE_TTL_MS) {
+        return cachedStats;
+    }
+
+    // Fetch fresh stats
+    const stats: ClientStats = {
+        guilds: AuroraClient.guilds.cache.size,
+        ping: AuroraClient.ws.ping,
+        cachedUsers: AuroraClient.users.cache.size,
+        commandsRegistered: AuroraClient.commands.size,
+        uptime: process.uptime(),
+        lastCommandTimestamp: AuroraClient.lastCommandTimestamp,
+    };
+
+    // Update cache
+    cachedStats = stats;
+    lastFetchTime = now;
+
+    return stats;
+}
+
+/**
+ * Clear the stats cache (useful for testing)
+ */
+export function clearStatsCache(): void {
+    cachedStats = null;
+    lastFetchTime = 0;
+}