fix: resolve post-merge build errors across WebApp and UI projects

- WebApp: AddMicrosoftIdentityWebApp requires AddAuthentication() first
- WebApp: GetAccessTokenForUserAsync parameter name mismatch
- UI/Vocabulary: stub unimplemented DuplicateGroup, BulkUpdateLemmas features
- Shared: UpdateVocabularyWordTermsAsync takes string PK (not int)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: davidortinau

src/SentenceStudio.Shared/Data/LearningResourceRepository.cs

@@ -744,7 +744,7 @@ public async Task<bool> UpdateVocabularyWordAsync(VocabularyWord word)
     /// <summary>
     /// Updates vocabulary word terms by ID, avoiding context tracking issues
     /// </summary>
-    public async Task<bool> UpdateVocabularyWordTermsAsync(int wordId, string targetTerm, string nativeTerm)
+    public async Task<bool> UpdateVocabularyWordTermsAsync(string wordId, string targetTerm, string nativeTerm)
     {
         using var scope = _serviceProvider.CreateScope();
         var db = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();

src/SentenceStudio.UI/Pages/Vocabulary.razor

@@ -912,8 +912,10 @@ else
 
         try
         {
-            duplicateGroups = await ResourceRepo.GetDuplicateGroupsAsync();
-            cleanupStatus = "";
+            // TODO: Implement duplicate detection (#future)
+            duplicateGroups = new List<DuplicateGroup>();
+            cleanupStatus = "Duplicate detection not yet implemented.";
+            await Task.CompletedTask;
         }
         catch (Exception ex)
         {
@@ -943,7 +945,7 @@ else
             var keeper = sorted.First();
             var deleteIds = sorted.Skip(1).Select(w => w.Word.Id).ToList();
 
-            int deleted = await ResourceRepo.MergeVocabularyWordsAsync(keeper.Word.Id, deleteIds);
+            int deleted = 0; // TODO: Implement MergeVocabularyWordsAsync (#future)
             cleanupResults.Add($"Merged '{group.NormalizedTerm}': kept 1, removed {deleted}");
 
             duplicateGroups.Remove(group);
@@ -986,7 +988,7 @@ else
                 var keeper = sorted.First();
                 var deleteIds = sorted.Skip(1).Select(w => w.Word.Id).ToList();
 
-                int deleted = await ResourceRepo.MergeVocabularyWordsAsync(keeper.Word.Id, deleteIds);
+                int deleted = 0; // TODO: Implement MergeVocabularyWordsAsync (#future)
                 totalMerged += deleted;
             }
             catch (Exception ex)
@@ -1090,7 +1092,7 @@ Return JSON like: {{""lemmas"": [{{""id"": 1, ""lemma"": ""dictionary form""}},
 
                         if (lemmaUpdates.Any())
                         {
-                            int batchUpdated = await ResourceRepo.BulkUpdateLemmasAsync(lemmaUpdates);
+                            int batchUpdated = 0; // TODO: Implement BulkUpdateLemmasAsync (#future)
                             updated += batchUpdated;
                         }
                     }
@@ -1312,4 +1314,8 @@ Return JSON like: {{""lemmas"": [{{""id"": 1, ""lemma"": ""dictionary form""}},
             _ => "Unknown"
         };
     }
+
+    private record DuplicateWordInfo(VocabularyWord Word, int ResourceCount, double EncodingScore);
+
+    private record DuplicateGroup(string NormalizedTerm, List<DuplicateWordInfo> Words);
 }

src/SentenceStudio.WebApp/Auth/AuthenticatedApiDelegatingHandler.cs

@@ -29,7 +29,7 @@ protected override async Task<HttpResponseMessage> SendAsync(
                      ?? throw new InvalidOperationException(
                          "DownstreamApi:Scopes must be configured when Entra ID auth is active.");
 
-        var token = await _tokenAcquisition.GetAccessTokenForUserAsync(scopes, cancellationToken: cancellationToken);
+        var token = await _tokenAcquisition.GetAccessTokenForUserAsync(scopes);
         request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
 
         return await base.SendAsync(request, cancellationToken);

src/SentenceStudio.WebApp/Program.cs

@@ -1,5 +1,6 @@
 using ElevenLabs;
 using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Authentication.OpenIdConnect;
 using Microsoft.Extensions.AI;
 using Microsoft.Identity.Web;
 using Microsoft.Identity.Web.UI;
@@ -62,7 +63,8 @@
             + "Add a 'DownstreamApi:Scopes' array to appsettings.json or user-secrets.");
     }
 
-    builder.Services.AddMicrosoftIdentityWebApp(builder.Configuration.GetSection("AzureAd"))
+    builder.Services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
+        .AddMicrosoftIdentityWebApp(builder.Configuration.GetSection("AzureAd"))
         .EnableTokenAcquisitionToCallDownstreamApi(downstreamScopes)
         .AddDistributedTokenCaches();