Fix AI document citation links duplicate endpoint name error

src/CrestApps.Core.Docs/docs/changelog/1.1.0.md

@@ -18,3 +18,7 @@ page will be updated as changes land after 1.0.0.
 ## Highlights
 
 - upgrades the framework's dependency baseline, including YesSql 6.0 (new `ISession.SaveAsync` signature), the Model Context Protocol 2.0 packages, the GitHub Copilot SDK 1.0.8 (new `PermissionsApi.SetAllowAllAsync` mode-based API), Anthropic 12.39.0, OllamaSharp 5.4.30, the .NET 10.0.10 runtime/extension packages, and the `Microsoft.Extensions.AI` 10.8.3 packages
+
+## Fixes
+
+- fixes AI document citation links throwing `System.InvalidOperationException: The following endpoints with a duplicate endpoint name were found` in multi-tenant hosts. `DocumentAIReferenceLinkResolver` no longer resolves the download link by endpoint name (which forced ASP.NET Core to validate global endpoint-name uniqueness and failed when other modules registered the same named API endpoints across tenants); it now builds the path directly from the static `DownloadAIDocument.RoutePattern`, respecting the request `PathBase`.

src/Primitives/CrestApps.Core.AI.Documents/Endpoints/DownloadAIDocument.cs

@@ -17,14 +17,19 @@ public static class DownloadAIDocument
 {
     public const string DefaultRouteName = "DownloadAIDocument";
 
+    /// <summary>
+    /// The static route pattern mapped for the AI document download endpoint.
+    /// </summary>
+    public const string RoutePattern = "ai/documents/{documentId}/download";
+
     /// <summary>
     /// Adds the shared AI document download endpoint used by citation links.
     /// </summary>
     /// <param name="builder">The builder.</param>
     /// <param name="routeName">The route name.</param>
     public static IEndpointRouteBuilder AddDownloadAIDocumentEndpoint(this IEndpointRouteBuilder builder, string routeName = DefaultRouteName)
     {
-        var endpoint = builder.MapGet("ai/documents/{documentId}/download", HandleAsync);
+        var endpoint = builder.MapGet(RoutePattern, HandleAsync);
 
         if (!string.IsNullOrEmpty(routeName))
         {

src/Primitives/CrestApps.Core.AI.Documents/Services/DocumentAIReferenceLinkResolver.cs

@@ -1,7 +1,6 @@
 using CrestApps.Core.AI.Documents.Endpoints;
 using CrestApps.Core.AI.Profiles;
 using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Routing;
 
 namespace CrestApps.Core.AI.Documents.Services;
 
@@ -10,19 +9,14 @@ namespace CrestApps.Core.AI.Documents.Services;
 /// </summary>
 public sealed class DocumentAIReferenceLinkResolver : IAIReferenceLinkResolver
 {
-    private readonly LinkGenerator _linkGenerator;
     private readonly IHttpContextAccessor _httpContextAccessor;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="DocumentAIReferenceLinkResolver"/> class.
     /// </summary>
-    /// <param name="linkGenerator">The link generator.</param>
     /// <param name="httpContextAccessor">The http context accessor.</param>
-    public DocumentAIReferenceLinkResolver(
-        LinkGenerator linkGenerator,
-        IHttpContextAccessor httpContextAccessor)
+    public DocumentAIReferenceLinkResolver(IHttpContextAccessor httpContextAccessor)
     {
-        _linkGenerator = linkGenerator;
         _httpContextAccessor = httpContextAccessor;
     }
 
@@ -38,12 +32,17 @@ public string ResolveLink(string referenceId, IDictionary<string, object> metada
             return null;
         }
 
-        return _linkGenerator.GetPathByName(
-            _httpContextAccessor.HttpContext,
-            DownloadAIDocument.DefaultRouteName,
-            new RouteValueDictionary
-            {
-                ["documentId"] = referenceId,
-            });
+        // Build the path directly from the static route pattern instead of resolving by endpoint
+        // name. Name-based link generation forces ASP.NET Core to validate that every endpoint name
+        // is globally unique, which throws in multi-tenant hosts where other modules register the
+        // same named API endpoints across tenants.
+        var relativePath = "/" + DownloadAIDocument.RoutePattern.Replace(
+            "{documentId}",
+            Uri.EscapeDataString(referenceId),
+            StringComparison.Ordinal);
+
+        var pathBase = _httpContextAccessor.HttpContext?.Request.PathBase ?? PathString.Empty;
+
+        return pathBase.Add(relativePath).Value;
     }
 }