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/tests/placeholder.test.ts

@@ -15,7 +15,7 @@ import {
   pageResult,
   retryWithBackoff,
 } from "@bete/shared/utils";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 
 // ─── Backend middleware ──────────────────────────────────────────────────────
 import { asyncHandler, requireParam } from "../src/shared/middlewares/index.js";