custom login implementation, period-based timetable layout with overlap handling, enhanced error dialogs, and unified bottom sheets

lib/view/pages/timetable/details/bottom_sheet.dart

@@ -1,51 +1,32 @@
 import 'package:flutter/material.dart';
 
+/// Shows a modal bottom sheet for an appointment, matching the design of the
+/// other sheets in the app (file details, file actions, overflow lessons):
+/// drag handle on top, default theme background, ListTile-style header
+/// followed by a divider, scrollable body below.
 void showAppointmentBottomSheet(
   BuildContext context, {
-  required Widget Function(BuildContext context) header,
-  required SliverChildListDelegate Function(BuildContext context) body,
+  required Widget header,
+  required List<Widget> Function(BuildContext sheetContext) children,
 }) {
   showModalBottomSheet<void>(
     context: context,
     isScrollControlled: true,
+    showDragHandle: true,
     useSafeArea: true,
-    backgroundColor: Theme.of(context).colorScheme.surface,
-    builder: (sheetContext) => DraggableScrollableSheet(
-      expand: false,
-      initialChildSize: 0.4,
-      minChildSize: 0.2,
-      maxChildSize: 0.7,
-      snap: true,
-      snapSizes: const [0.4],
-      builder: (_, scrollController) => CustomScrollView(
-        controller: scrollController,
-        slivers: [
-          SliverPersistentHeader(
-            pinned: true,
-            delegate: _StickyHeader(child: header(sheetContext)),
-          ),
-          SliverList(delegate: body(sheetContext)),
-        ],
+    builder: (sheetContext) => SafeArea(
+      child: SingleChildScrollView(
+        padding: const EdgeInsets.only(bottom: 16),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            header,
+            const Divider(height: 1),
+            ...children(sheetContext),
+          ],
+        ),
       ),
     ),
   );
 }
-
-class _StickyHeader extends SliverPersistentHeaderDelegate {
-  _StickyHeader({required this.child});
-  final Widget child;
-
-  @override
-  double get minExtent => 100;
-  @override
-  double get maxExtent => 100;
-
-  @override
-  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) => Material(
-        color: Theme.of(context).colorScheme.surface,
-        child: SizedBox.expand(child: child),
-      );
-
-  @override
-  bool shouldRebuild(covariant _StickyHeader oldDelegate) => oldDelegate.child != child;
-}