Address validation feedback on MCP token fixes

Agent-Logs-Url: https://github.com/IntelliTect/EssentialCSharp.Web/sessions/1309ce59-f673-4f1a-b124-e849af2f4737

Co-authored-by: BenjaminMichaelis <22186029+BenjaminMichaelis@users.noreply.github.com>

Author: Copilot

EssentialCSharp.Web/Areas/Identity/Pages/Account/Manage/McpAccess.cshtml

@@ -62,7 +62,7 @@
                     <label asp-for="ExpiresOn" class="form-label">Expiry Date</label>
                     <input asp-for="ExpiresOn" type="date" class="form-control" max="@Model.MaxExpiresOn.ToString("yyyy-MM-dd")" />
                     <span asp-validation-for="ExpiresOn" class="text-danger"></span>
-                    <div class="form-text">MCP tokens default to @McpApiTokenService.DefaultLifetimeMonths months and cannot exceed @McpApiTokenService.DefaultLifetimeMonths months from today. The token expires at end of day (UTC) on the selected date.</div>
+                    <div class="form-text">MCP tokens expire after @McpApiTokenService.DefaultLifetimeMonths months by default, with a maximum lifetime of @McpApiTokenService.DefaultLifetimeMonths months from today. The token expires at end of day (UTC) on the selected date.</div>
                 </div>
                 <button type="submit" class="btn btn-primary">Create Token</button>
             </form>

EssentialCSharp.Web/Services/McpApiTokenService.cs

@@ -10,7 +10,7 @@ namespace EssentialCSharp.Web.Services;
 public class McpApiTokenService(EssentialCSharpWebContext db)
 {
     public const int DefaultLifetimeMonths = 6;
-    public static string MaxExpiryValidationMessage => $"MCP tokens can expire at most {DefaultLifetimeMonths} months from today.";
+    public static readonly string MaxExpiryValidationMessage = $"MCP tokens can expire at most {DefaultLifetimeMonths} months from today.";
 
     public sealed record ResolvedMcpApiToken(Guid TokenId, string UserId);