Performance: push ORDER BY/TAKE into SQL for hot-path reads

- IInAppNotificationRepository: typed repo with GetPagedAsync, GetRecentAsync, GetUnreadAsync
  — bell dropdown no longer loads all notifications then slices in C#
- Add compound indexes on InAppNotifications(CompanyId, IsDeleted, CreatedAt) and
  (CompanyId, IsDeleted, IsRead); ContactSubmissions(CompanyId, IsDeleted, CreatedAt)
- PlainRepository.GetAllAsync/FindAsync: add AsNoTracking (Announcements, Tips, ReleaseNotes)
- AiUsageReportController: replace GetAllAsync + C# Where with FindAsync (SQL-level filter)

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

src/PowderCoating.Web/Controllers/AiUsageReportController.cs

@@ -33,8 +33,7 @@ public class AiUsageReportController : Controller
     {
         try
         {
-            var companies = (await _unitOfWork.Companies.GetAllAsync(ignoreQueryFilters: true))
-                .Where(c => !c.IsDeleted)
+            var companies = (await _unitOfWork.Companies.FindAsync(c => !c.IsDeleted, ignoreQueryFilters: true))
                 .Select(c => new { c.Id, c.CompanyName, c.SubscriptionPlan, c.IsActive })
                 .ToList();
 

src/PowderCoating.Web/Controllers/InAppNotificationsController.cs

@@ -18,92 +18,88 @@ public class InAppNotificationsController : Controller
     }
 
     /// <summary>
-    /// Displays the paginated notification history page (read and unread). SuperAdmins see only platform-level notifications (CompanyId 0) via IgnoreQueryFilters; regular users rely on the global query filter for tenant isolation.
+    /// Displays the paginated notification history page (read and unread). SuperAdmins see only
+    /// platform-level notifications (CompanyId 0); regular users rely on the global query filter.
+    /// ORDER BY / SKIP / TAKE run in SQL via GetPagedAsync — no full-table load.
     /// </summary>
     public async Task<IActionResult> Index(int pageNumber = 1, int pageSize = 25)
     {
         pageNumber = Math.Max(1, pageNumber);
         pageSize = pageSize is 10 or 25 or 50 ? pageSize : 25;
 
-        var all = _tenant.IsPlatformAdmin()
-            ? (await _unitOfWork.InAppNotifications.FindAsync(
-                n => !n.IsDeleted && n.CompanyId == 0, ignoreQueryFilters: true)).ToList()
-            : (await _unitOfWork.InAppNotifications.GetAllAsync()).ToList();
-
-        var totalCount = all.Count;
+        var isPlatformAdmin = _tenant.IsPlatformAdmin();
+        var (items, totalCount) = await _unitOfWork.InAppNotifications
+            .GetPagedAsync(isPlatformAdmin, pageNumber, pageSize);
 
         var tz = ViewBag.CompanyTimeZone as string;
-        var items = all
-            .OrderByDescending(n => n.CreatedAt)
-            .Skip((pageNumber - 1) * pageSize)
-            .Take(pageSize)
-            .Select(n => new
-            {
-                n.Id,
-                n.Title,
-                n.Message,
-                n.Link,
-                n.NotificationType,
-                n.IsRead,
-                n.ReadAt,
-                CreatedAt = n.CreatedAt
-            })
-            .ToList();
+        var vm = items.Select(n => new
+        {
+            n.Id,
+            n.Title,
+            n.Message,
+            n.Link,
+            n.NotificationType,
+            n.IsRead,
+            n.ReadAt,
+            CreatedAt = n.CreatedAt
+        }).ToList();
 
         ViewBag.TotalCount = totalCount;
         ViewBag.PageNumber = pageNumber;
         ViewBag.PageSize = pageSize;
         ViewBag.TotalPages = (int)Math.Ceiling((double)totalCount / pageSize);
-        return View(items);
+        return View(vm);
     }
 
     /// <summary>
-    /// AJAX endpoint that returns the 20 most recent notifications (read and unread) for the bell dropdown.
+    /// AJAX endpoint for the bell dropdown — returns the 20 most recent notifications.
+    /// ORDER BY and TAKE run in SQL; no full-table load.
     /// </summary>
     [HttpGet]
     public async Task<IActionResult> Recent()
     {
-        var all = _tenant.IsPlatformAdmin()
-            ? (await _unitOfWork.InAppNotifications.FindAsync(
-                n => !n.IsDeleted && n.CompanyId == 0, ignoreQueryFilters: true)).ToList()
-            : (await _unitOfWork.InAppNotifications.GetAllAsync()).ToList();
+        var isPlatformAdmin = _tenant.IsPlatformAdmin();
+        var items = await _unitOfWork.InAppNotifications.GetRecentAsync(isPlatformAdmin, take: 20);
 
         var tz = ViewBag.CompanyTimeZone as string;
-        var items = all
-            .OrderByDescending(n => n.CreatedAt)
-            .Take(20)
-            .Select(n => new { n.Id, n.Title, n.Message, n.Link, n.NotificationType, n.IsRead, n.CreatedAt })
-            .ToList();
-
         var unreadCount = items.Count(n => !n.IsRead);
-        return Json(new { count = unreadCount, items = items.Select(n => new {
-            n.Id, n.Title, n.Message, n.Link, n.NotificationType, n.IsRead,
-            CreatedAt = n.CreatedAt.Tz(tz).ToString("MMM d, h:mm tt")
-        }) });
+        return Json(new
+        {
+            count = unreadCount,
+            items = items.Select(n => new
+            {
+                n.Id, n.Title, n.Message, n.Link, n.NotificationType, n.IsRead,
+                CreatedAt = n.CreatedAt.Tz(tz).ToString("MMM d, h:mm tt")
+            })
+        });
     }
 
     /// <summary>
-    /// AJAX endpoint that returns only unread notifications (up to 20) plus an unread count for the bell badge.
+    /// AJAX endpoint for the bell badge — returns unread count plus up to 20 unread items.
+    /// COUNT and ORDER BY / TAKE run in SQL; no full-table load.
     /// </summary>
     [HttpGet]
     public async Task<IActionResult> Unread()
     {
-        var items = _tenant.IsPlatformAdmin()
-            ? (await _unitOfWork.InAppNotifications.FindAsync(
-                n => !n.IsDeleted && n.CompanyId == 0 && !n.IsRead, ignoreQueryFilters: true))
-                .OrderByDescending(n => n.CreatedAt).Take(20).ToList()
-            : (await _unitOfWork.InAppNotifications.FindAsync(n => !n.IsRead))
-                .OrderByDescending(n => n.CreatedAt).Take(20).ToList();
+        var isPlatformAdmin = _tenant.IsPlatformAdmin();
+        var (items, unreadCount) = await _unitOfWork.InAppNotifications
+            .GetUnreadAsync(isPlatformAdmin, take: 20);
 
         var tz = ViewBag.CompanyTimeZone as string;
-        return Json(new { count = items.Count, items = items.Select(n => new {
-            n.Id, n.Title, n.Message, n.Link, n.NotificationType,
-            CreatedAt = n.CreatedAt.Tz(tz).ToString("MMM d, h:mm tt")
-        }) });
+        return Json(new
+        {
+            count = unreadCount,
+            items = items.Select(n => new
+            {
+                n.Id, n.Title, n.Message, n.Link, n.NotificationType,
+                CreatedAt = n.CreatedAt.Tz(tz).ToString("MMM d, h:mm tt")
+            })
+        });
     }
 
     /// <summary>
-    /// Marks a single notification as read. Tenant isolation is enforced manually for SuperAdmins (CompanyId 0 filter) because IgnoreQueryFilters bypasses the global company filter.
+    /// Marks a single notification as read. Tenant isolation is enforced manually for SuperAdmins
+    /// (CompanyId 0 filter) because IgnoreQueryFilters bypasses the global company filter.
     /// </summary>
     [HttpPost]
     public async Task<IActionResult> MarkRead(int id)