Fix empty-state button/text on list pages when search returns no results

Show 'Add Your First X' and onboarding copy only when the list is truly
empty. When a search or filter is active with no results, show 'Add X'
and 'No X match your search/filters' instead.

Affected: Customers (table + mobile views), Equipment, Inventory.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Views/Customers/Index.cshtml

@@ -52,12 +52,13 @@
     <div class="card-body p-0">
         @if (!Model.Items.Any())
         {
+            var isCustomerListFiltered = !string.IsNullOrEmpty(ViewBag.SearchTerm as string);
             <div class="text-center py-5">
                 <i class="bi bi-inbox" style="font-size: 4rem; color: #d1d5db;"></i>
                 <h5 class="mt-3 text-muted">No customers found</h5>
-                <p class="text-muted mb-4">Get started by adding your first customer</p>
+                <p class="text-muted mb-4">@(isCustomerListFiltered ? "No customers match your search." : "Get started by adding your first customer.")</p>
                 <a asp-action="Create" class="btn btn-primary">
-                    <i class="bi bi-plus-circle me-2"></i>Add Your First Customer
+                    <i class="bi bi-plus-circle me-2"></i>@(isCustomerListFiltered ? "Add Customer" : "Add Your First Customer")
                 </a>
             </div>
         }
@@ -187,9 +188,9 @@
                     <div class="text-center py-5">
                         <i class="bi bi-inbox" style="font-size: 4rem; color: #d1d5db;"></i>
                         <h5 class="mt-3 text-muted">No customers found</h5>
-                        <p class="text-muted mb-4">Get started by adding your first customer</p>
+                        <p class="text-muted mb-4">@(isCustomerListFiltered ? "No customers match your search." : "Get started by adding your first customer.")</p>
                         <a asp-action="Create" class="btn btn-primary">
-                            <i class="bi bi-plus-circle me-2"></i>Add Your First Customer
+                            <i class="bi bi-plus-circle me-2"></i>@(isCustomerListFiltered ? "Add Customer" : "Add Your First Customer")
                         </a>
                     </div>
                 }

src/PowderCoating.Web/Views/Equipment/Index.cshtml

@@ -61,12 +61,13 @@
     <div class="card-body p-0">
         @if (!Model.Items.Any())
         {
+            var isEquipmentListFiltered = !string.IsNullOrEmpty(ViewBag.SearchTerm as string) || ViewBag.StatusFilter != null;
             <div class="text-center py-5">
                 <i class="bi bi-inbox" style="font-size: 4rem; color: #d1d5db;"></i>
                 <h5 class="mt-3 text-muted">No equipment found</h5>
-                <p class="text-muted mb-4">Get started by adding your first equipment</p>
+                <p class="text-muted mb-4">@(isEquipmentListFiltered ? "No equipment matches your search." : "Get started by adding your first equipment.")</p>
                 <a asp-action="Create" class="btn btn-primary">
-                    <i class="bi bi-plus-circle me-2"></i>Add Your First Equipment
+                    <i class="bi bi-plus-circle me-2"></i>@(isEquipmentListFiltered ? "Add Equipment" : "Add Your First Equipment")
                 </a>
             </div>
         }

src/PowderCoating.Web/Views/Inventory/Index.cshtml

@@ -191,12 +191,13 @@
     <div class="card-body p-0">
         @if (!Model.Items.Any())
         {
+            var isInventoryFiltered = !string.IsNullOrEmpty(ViewBag.SearchTerm as string) || !string.IsNullOrEmpty(ViewBag.Category as string) || lowStockOnly;
             <div class="text-center py-5">
                 <i class="bi bi-inbox" style="font-size: 4rem; color: #d1d5db;"></i>
                 <h5 class="mt-3 text-muted">No inventory items found</h5>
-                <p class="text-muted mb-4">Get started by adding your first inventory item</p>
+                <p class="text-muted mb-4">@(isInventoryFiltered ? "No items match your current filters." : "Get started by adding your first inventory item.")</p>
                 <a asp-action="Create" class="btn btn-primary">
-                    <i class="bi bi-plus-circle me-2"></i>Add Your First Item
+                    <i class="bi bi-plus-circle me-2"></i>@(isInventoryFiltered ? "Add Item" : "Add Your First Item")
                 </a>
             </div>
         }