Improve toast duration and speaker override samples

MeetingAssistant.Tests/SpeakerIdentityServiceTests.cs

@@ -350,6 +350,48 @@ public sealed class SpeakerIdentityServiceTests
         Assert.Contains(saved.Snippets, snippet => snippet.WavBytes.SequenceEqual(new byte[] { 8, 8, 8 }));
     }
 
+    [Fact]
+    public async Task SpeakerOverrideExtractsOnlyBestContinuousSourceSpanWhenNoLiveSampleExists()
+    {
+        await using var fixture = await SpeakerIdentityFixture.CreateAsync();
+        var service = fixture.CreateService();
+        var request = fixture.CreateRequest(
+            ["Sabrina"],
+            [
+                new TranscriptionSegment(TimeSpan.Zero, TimeSpan.FromSeconds(10), "Guest-01", "short start"),
+                new TranscriptionSegment(TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(20), "Guest-02", "someone else"),
+                new TranscriptionSegment(TimeSpan.FromSeconds(60), TimeSpan.FromSeconds(80), "Guest-01", "continuous first part"),
+                new TranscriptionSegment(TimeSpan.FromSeconds(80.5), TimeSpan.FromSeconds(92), "Guest-01", "continuous second part"),
+                new TranscriptionSegment(TimeSpan.FromSeconds(180), TimeSpan.FromSeconds(190), "Guest-01", "short end")
+            ]);
+
+        await service.ApplySpeakerOverrideAsync(request, "Guest-01", "Sabrina", CancellationToken.None);
+
+        Assert.Equal(1, fixture.SnippetExtractor.ExtractCalls);
+        Assert.Collection(
+            fixture.SnippetExtractor.LastSpeakerSegments,
+            segment => Assert.Equal(TimeSpan.FromSeconds(60), segment.Start),
+            segment => Assert.Equal(TimeSpan.FromSeconds(80.5), segment.Start));
+    }
+
+    [Fact]
+    public async Task SpeakerOverrideDoesNotCreateNamedIdentityWhenSecondaryValidationRejectsSample()
+    {
+        await using var fixture = await SpeakerIdentityFixture.CreateAsync();
+        fixture.MatchValidator.SampleIsValid = false;
+        var service = fixture.CreateService();
+        var request = fixture.CreateRequest(
+            ["Sabrina"],
+            [
+                new TranscriptionSegment(TimeSpan.Zero, TimeSpan.FromSeconds(31), "Guest-01", "long enough source sample")
+            ]);
+
+        await service.ApplySpeakerOverrideAsync(request, "Guest-01", "Sabrina", CancellationToken.None);
+
+        Assert.Equal(1, fixture.MatchValidator.ValidateSampleCalls);
+        Assert.Empty(await fixture.Context.SpeakerIdentities.ToListAsync());
+    }
+
     [Fact]
     public async Task SpeakerOverrideDoesNotCreateNamedIdentityWithoutSourceSample()
     {
@@ -800,6 +842,8 @@ public sealed class SpeakerIdentityServiceTests
     {
         public int ExtractCalls { get; private set; }
 
+        public IReadOnlyList<TranscriptionSegment> LastSpeakerSegments { get; private set; } = [];
+
         public Task<byte[]> ExtractSnippetAsync(
             string audioPath,
             IReadOnlyList<TranscriptionSegment> speakerSegments,
@@ -811,6 +855,7 @@ public sealed class SpeakerIdentityServiceTests
             }
 
             ExtractCalls++;
+            LastSpeakerSegments = speakerSegments.ToList();
             return Task.FromResult<byte[]>([7, 8, 9]);
         }
     }
@@ -845,10 +890,13 @@ public sealed class SpeakerIdentityServiceTests
     {
         public bool SampleIsValid { get; set; } = true;
 
+        public int ValidateSampleCalls { get; private set; }
+
         public Task<bool> ValidateSampleAsync(
             byte[] wavBytes,
             CancellationToken cancellationToken)
         {
+            ValidateSampleCalls++;
             return Task.FromResult(SampleIsValid);
         }