refactored and condensed technical documentation and comments across the codebase to improve readability

lib/main.dart

@@ -243,11 +243,8 @@ class _MainState extends State<Main> {
     });
   }
 
-  /// Fires a background credential check against Marianum Connect — runs in
-  /// the background so it never blocks the cold-start path. A 401 means the
-  /// password has been rotated server-side; the validator wipes the local
-  /// session and we flip the account bloc back to `loggedOut`, which sends
-  /// the user to the login screen.
+  /// Warms the core caches (timetable, chat list, files root) in the
+  /// background so the first screen render hits populated data.
   void _prefetchBaseData(BuildContext context) {
     context.read<TimetableBloc>().refresh();
     unawaited(context.read<ChatListBloc>().refresh(silent: true));
@@ -265,6 +262,9 @@ class _MainState extends State<Main> {
     );
   }
 
+  /// Background credential check: a 401 means the password was rotated
+  /// server-side, so the validator wipes the local session and flips the
+  /// account bloc to `loggedOut` (sending the user to the login screen).
   void _scheduleSessionValidation(AccountBloc accountBloc) {
     unawaited(
       SessionValidator.probeStored(