GuestLog - StayEntry detail view and improvements:

- Added detail view for StayEntries.
- Added button to delete StayEntries.
- Improve queries of StayEntries using a "query config" record.
- Enabled LazyLoading for all database relations. This will make easier to find cases where required relations aren't explicitly loaded.

src/Somnia.GuestLog/Components/Forms/StayEntryForm.razor

@@ -1,5 +1,5 @@
+@using System.Diagnostics
 @using FluentValidation;
-@using Microsoft.AspNetCore.SignalR
 @using Somnia.GuestLog.Models.DTOs;
 @using Somnia.GuestLog.Services;
 @using Somnia.GuestLog.Validators;
@@ -143,7 +143,7 @@
     {
         await _form.ValidateAsync();
 
-        if (Model.GuestDocuments.Count == 0)
+        if (Model.GuestDocuments is null || Model.GuestDocuments.Count == 0)
         {
             snackbar.Add("At least 1 guest is required!", MudBlazor.Severity.Warning);
             return false;
@@ -198,12 +198,21 @@
         }
 
         //Check if this guest is already added.
-        bool alreadyAdded = Model.GuestDocuments.Any(e => e.DocumentType == resultData.DocumentType
-            && e.DocumentNum == resultData.DocumentNum);
-        if (alreadyAdded)
+        if (Model.GuestDocuments is not null && Model.GuestDocuments.Count > 0)
         {
-            snackbar.Add("GuestDocument already added!", MudBlazor.Severity.Warning);
-            return;
+            bool alreadyAdded = Model.GuestDocuments.Any(e => e.DocumentType == resultData.DocumentType
+                && e.DocumentNum == resultData.DocumentNum);
+            if (alreadyAdded)
+            {
+                snackbar.Add("GuestDocument already added!", MudBlazor.Severity.Warning);
+                return;
+            }
+        }
+
+        //Init List.
+        if (Model.GuestDocuments is null)
+        {
+            Model.GuestDocuments = [];
         }
 
         Model.GuestDocuments.Add(resultData);
@@ -211,8 +220,12 @@
 
     private void BtnDeleteGuest(string docType, string docNum)
     {
+        Debug.Assert(Model.GuestDocuments is not null);
+
         //Filter out given GuestDocument from model.
-        Model.GuestDocuments = Model.GuestDocuments.Where(e => !(e.DocumentType == docType && e.DocumentNum == docNum)).ToList();
+        Model.GuestDocuments = Model.GuestDocuments
+            .Where(e => !(e.DocumentType == docType && e.DocumentNum == docNum))
+            .ToList();
     }
 
     #endregion