Fixat årsskifte med veckorna

Aberwyn/Controllers/FoodMenuController.cs

@@ -220,8 +220,28 @@ namespace Aberwyn.Controllers
             var menuService = _menuService;
 
             var today = DateTime.Today;
-            int resolvedWeek = week ?? ISOWeek.GetWeekOfYear(today);
-            int resolvedYear = year ?? today.Year;
+
+            // Starta alltid från ett GILTIGT datum
+            DateTime referenceDate;
+
+            if (week.HasValue && year.HasValue)
+            {
+                // Om week < 1 eller > 53 – tolka det som navigering
+                // från närliggande vecka i stället för att krascha
+                int safeWeek = Math.Clamp(week.Value, 1, 53);
+                referenceDate = ISOWeek.ToDateTime(year.Value, safeWeek, DayOfWeek.Monday);
+
+                // Justera datumet med differensen (ex: week=0 → -1 vecka)
+                referenceDate = referenceDate.AddDays((week.Value - safeWeek) * 7);
+            }
+            else
+            {
+                referenceDate = today;
+            }
+
+            // Normalisera alltid via datum
+            int resolvedWeek = ISOWeek.GetWeekOfYear(referenceDate);
+            int resolvedYear = ISOWeek.GetYear(referenceDate);
 
             var menus = menuService.GetWeeklyMenu(resolvedWeek, resolvedYear);