fix: base64 uploads, audit log noise, and stale chunk reloads (#69)

## Summary

- **Base64 cover image uploads broken for books, shows, manga, and music** — a premature `validateStringLength` check ran before the data URL detection, rejecting all base64 images with a 2,048-char URL limit error. Also fixed the size calculation to extract only the base64 portion after the comma (matching the correct pattern already in `game.service.ts`).
- **Audit log flooded with expected 401s on `/api/auth/me`** — these occur during normal token refresh flow and are not genuine security events. Excluded this URL from the global 401/403 audit log handler.
- **ChunkLoadError spam after deployments** — when Angular lazy-loaded chunks are missing (stale cache after a redeploy), the global error handler now detects `ChunkLoadError` and silently reloads the page instead of logging the error and sending it to the API/Discord.

## Test plan

- [ ] Upload a base64 cover image for a book, show, manga, and music item — should succeed
- [ ] Verify `/api/auth/me` 401s no longer appear in the audit log
- [ ] Deploy a new build and confirm stale-chunk users are silently reloaded

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #69
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/frontend/src/app/services/global-error-handler.service.ts

@@ -12,6 +12,11 @@ export class GlobalErrorHandler implements ErrorHandler {
   private toast = inject(ToastService);
 
   handleError(error: Error): void {
+    if (error.name === 'ChunkLoadError' || error.message.includes('Loading chunk')) {
+      window.location.reload();
+      return;
+    }
+
     console.error('Global error caught:', error);
 
     // Show user-friendly error message