feat: add debug console for frontend and backend logs

Added a comprehensive debug console feature that captures and displays
logs from both the frontend and backend in a unified interface.

Frontend changes:
- Created DebugConsole component with real-time log display
- Added debugConsoleStore for state management and console capture
- Integrated console into main layout
- Added toggle button in StatusBar with console icon
- Implemented Ctrl+` keyboard shortcut to open/close console
- Features: log filtering by level, auto-scroll, timestamps, colour-coding

Backend changes:
- Added tracing and tracing-subscriber dependencies
- Created custom TauriLogLayer to emit Rust logs to frontend
- Integrated tracing subscriber in lib.rs setup
- Logs are forwarded via Tauri events (debug:log)

Key features:
- Circular buffer (max 1000 logs) prevents memory issues
- Frontend logs captured via console method overrides
- Backend logs forwarded from Rust tracing layer
- Log level filtering (debug, info, warn, error, all)
- Source badges distinguish frontend vs backend logs
- Colour-coded log levels for easy identification
- Auto-scroll toggle for inspecting older logs
- Clear logs button for resetting the console
- Beautiful dark-themed UI matching app aesthetic

Closes #126

src/routes/+page.svelte

@@ -31,6 +31,7 @@
   import AchievementNotification from "$lib/components/AchievementNotification.svelte";
   import AchievementsPanel from "$lib/components/AchievementsPanel.svelte";
   import UpdateNotification from "$lib/components/UpdateNotification.svelte";
+  import { debugConsoleStore } from "$lib/stores/debugConsole";
 
   let initialized = false;
   let updateNotification: UpdateNotification | undefined = $state(undefined);
@@ -230,6 +231,13 @@
       return;
     }
 
+    // Ctrl+` - Toggle debug console
+    if (event.ctrlKey && event.key === "`") {
+      event.preventDefault();
+      debugConsoleStore.toggle();
+      return;
+    }
+
     // Ctrl+E - Toggle editor panel (only when connected)
     if (event.ctrlKey && event.key === "e") {
       event.preventDefault();