Color-code drink buttons by category

Add a Drink.category field (beer, alc_free_beer, radler, alc_free_radler,
soft, water) and apply per-category gradient backgrounds to the booking
buttons so users can recognize drinks at a glance. Sort buttons by
category, shrink them to a 3:2 aspect ratio, and switch labels to more
verbose brand names (Sternburg Export, Ur-Krostitzer, etc.).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

gaehsnitz/suff.py

@@ -6,7 +6,7 @@ from django.contrib.admin.views.decorators import staff_member_required
 from django.contrib.auth import authenticate, login, logout
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth import get_user_model
-from django.db.models import F, Sum
+from django.db.models import Case, F, IntegerField, Sum, Value, When
 from django.http import Http404, HttpResponseRedirect
 from django.shortcuts import render
 from django.urls import reverse
@@ -173,7 +173,24 @@ def pin_view(request):
 @require_http_methods(["GET"])
 def me_view(request):
     phase = _require_open(request)
-    drinks = Drink.objects.filter(year=current_year()).order_by("name") if phase == "booking" else Drink.objects.none()
+    drinks = (
+        Drink.objects.filter(year=current_year())
+        .annotate(
+            category_order=Case(
+                When(category="beer", then=Value(0)),
+                When(category="alc_free_beer", then=Value(1)),
+                When(category="radler", then=Value(2)),
+                When(category="alc_free_radler", then=Value(3)),
+                When(category="soft", then=Value(4)),
+                When(category="water", then=Value(5)),
+                default=Value(99),
+                output_field=IntegerField(),
+            )
+        )
+        .order_by("category_order", "name")
+        if phase == "booking"
+        else Drink.objects.none()
+    )
     booked_drink = None
     booked_id = request.GET.get("booked")
     if booked_id: