Change log level to DEBUG in beta configuration and improve logging in LoginController.

backend/src/main/java/com/alttd/altitudeweb/controllers/login/LoginController.java

@@ -84,11 +84,13 @@ public class LoginController implements LoginApi {
     @Override
     public ResponseEntity<String> login(String code) {
         if (code == null) {
+            log.warn("Received null login code");
             return ResponseEntity.badRequest().build();
         }
 
         CacheEntry cacheEntry = cache.get(code);
         if (cacheEntry == null || cacheEntry.expiry().isBefore(Instant.now())) {
+            log.warn("Received invalid login code {}", code);
             return ResponseEntity.status(HttpStatus.FORBIDDEN).build();
         }
 
@@ -96,6 +98,7 @@ public class LoginController implements LoginApi {
 
         cache.remove(code);
 
+        log.debug("Generated token for user {}", cacheEntry.uuid);
         return ResponseEntity.ok(token);
     }