feat(notification): add admin rest management and deletion

Add revision-safe service and template APIs, channel mapping, and validated admin controls.

Ref: IT-1601

HrynCo.NotificationService.Web/Views/AdminServices/Edit.cshtml

@@ -6,7 +6,7 @@
     ViewData["EditorTitle"] = ViewData["Title"];
 }
 @section Breadcrumbs {
-    <nav aria-label="Breadcrumb"><ol class="breadcrumb"><li class="breadcrumb-item"><a href="/admin/services">Services</a></li>@if (!Model.IsNew) { <li class="breadcrumb-item"><a href="/admin/services/@Model.Id">@Model.Name</a></li> }<li class="breadcrumb-item active" aria-current="page">@ViewData["Title"]</li></ol></nav>
+    <nav aria-label="Breadcrumb" class="service-editor-breadcrumbs"><ol class="breadcrumb"><li class="breadcrumb-item"><a href="/admin/services">Services</a></li>@if (!Model.IsNew) { <li class="breadcrumb-item"><a href="/admin/services/@Model.Id">@Model.Name</a></li> }<li class="breadcrumb-item active" aria-current="page">@ViewData["Title"]</li></ol></nav>
 }
 <form asp-action="Save" id="serviceForm" method="post">
     @Html.AntiForgeryToken()
@@ -17,7 +17,7 @@
     <h3 class="h5">Language codes</h3>
     <p class="text-muted">Codes are case-sensitive and belong to this service. Existing template versions use these codes when sending. Renaming a service or code changes sender lookup; align publishers and email channel service names.</p>
     <div class="table-responsive">
-        <table class="table service-language-table"><thead><tr><th>Code</th><th>Versions</th><th class="service-language-actions">Actions</th></tr></thead><tbody id="serviceLanguages">
+        <table class="table admin-data-table service-language-table"><thead><tr><th scope="col">Code</th><th scope="col">Versions</th><th scope="col" class="service-language-actions">Actions</th></tr></thead><tbody id="serviceLanguages">
         @for (var i = 0; i < Model.Languages.Count; i++)
         {
             var countUnavailable = ViewData["LanguageCountsUnavailable"] is true && Model.Languages[i].Id != Guid.Empty;