Add stock availability display to product list and detail views

- Add total_available, total_reserved, total_free annotations to product queries
- Display free stock (green/red) with reserved count in product list
- Show detailed stock info in product detail page (moved to top)
- Make reservation count clickable to view filtered reservations
- Add product filter support to ReservationListView
- Add product link in reservation list for easy navigation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

myproject/inventory/views/reservation.py

@@ -6,6 +6,7 @@ Reservation (Резервирование товара) views - READ ONLY
 from django.views.generic import ListView
 from django.contrib.auth.mixins import LoginRequiredMixin
 from ..models import Reservation
+from products.models import Product
 
 
 class ReservationListView(LoginRequiredMixin, ListView):
@@ -19,7 +20,25 @@ class ReservationListView(LoginRequiredMixin, ListView):
     paginate_by = 20
 
     def get_queryset(self):
-        """Показываем все резервы со статусом 'reserved'"""
-        return Reservation.objects.filter(
+        """Показываем все резервы со статусом 'reserved', с опциональной фильтрацией по товару"""
+        queryset = Reservation.objects.filter(
             status='reserved'
-        ).select_related('product', 'warehouse', 'order_item', 'showcase').order_by('-reserved_at')
+        ).select_related('product', 'warehouse', 'order_item', 'showcase', 'product_kit').order_by('-reserved_at')
+
+        # Фильтрация по товару
+        product_id = self.request.GET.get('product')
+        if product_id:
+            queryset = queryset.filter(product_id=product_id)
+
+        return queryset
+
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        # Если фильтруем по товару, добавляем его в контекст
+        product_id = self.request.GET.get('product')
+        if product_id:
+            try:
+                context['filtered_product'] = Product.objects.get(pk=product_id)
+            except Product.DoesNotExist:
+                pass
+        return context