feat: update dependencies and improve dashboard functionality

- Added new dependencies for Next.js and lucide-react in pnpm-workspace.yaml.
- Refactored DashboardPage component to improve readability and error handling.
- Enhanced Header component to display error status with an alert icon.
- Updated MobileTabBar and Sidebar components to use a centralized tabs definition.
- Improved ChannelsView in dashboard-panel to handle channel fetching more cleanly.
- Fixed ActiveSpeaker type to use camelCase for userId.
- Updated MessagesPanel to handle guildId checks more gracefully.
- Adjusted API calls in dashboard and messages to align with backend expectations.
- Refined type definitions across various interfaces for consistency and clarity.

services/backend/src/modules/health/moderationMetrics.ts

@@ -4,7 +4,7 @@
  * Prometheus metrics for AI moderation pipeline.
  * Defined in backend (where prom-client is installed + /api/metrics endpoint).
  */
-import { Counter, Histogram, register } from "prom-client";
+import { Counter, Histogram } from "prom-client";
 
 // ── LLM Call Metrics ──
 export const llmCallsTotal = new Counter({