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/frontend/src/lib/api/dashboard.ts

@@ -26,6 +26,7 @@ export const dashboardApi = {
     const params = new URLSearchParams();
     if (limit) params.set("limit", String(limit));
     if (search) params.set("search", search);
+    // Backend reads req.query.guild_id (snake_case) — see createDashboardRouter in dashboard.routes.ts
     if (guildId) params.set("guild_id", guildId);
     const qs = params.toString();
     return api.get<PaginatedChannels>(