feat(ads/seo/release): v1.2.0 with live Google Ads, isolated ad profile, ads.txt, and SEO/AEO/GEO optimization

tests/Paca.Tests/Core/DualSubtitleComposerGateTests.cs

@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using Paca.Mobile.Core;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+public class DualSubtitleComposerGateTests
+{
+    [Fact]
+    public void Gate289_DualSubtitleComposer_AlignsOverlappingCues_Simultaneously()
+    {
+        var primaryCues = new List<SubtitleCue>
+        {
+            new(10.0, 15.0, "Hello world")
+        };
+        var secondaryCues = new List<SubtitleCue>
+        {
+            new(11.0, 14.0, "안녕하세요")
+        };
+
+        var composer = new DualSubtitleComposer(primaryCues, secondaryCues);
+
+        // At 12.0s, both are active
+        var active = composer.GetActiveDualCue(currentPosSec: 12.0);
+
+        Assert.NotNull(active);
+        Assert.Equal("Hello world", active!.PrimaryText);
+        Assert.Equal("안녕하세요", active.SecondaryText);
+        Assert.True(active.HasDual);
+    }
+
+    [Fact]
+    public void Gate290_DualSubtitleComposer_HandlesMissingSecondary_Gracefully()
+    {
+        var primaryCues = new List<SubtitleCue>
+        {
+            new(10.0, 15.0, "Hello world")
+        };
+        var secondaryCues = new List<SubtitleCue>
+        {
+            new(11.0, 14.0, "안녕하세요")
+        };
+
+        var composer = new DualSubtitleComposer(primaryCues, secondaryCues);
+
+        // At 10.5s, only primary is active
+        var active = composer.GetActiveDualCue(currentPosSec: 10.5);
+
+        Assert.NotNull(active);
+        Assert.Equal("Hello world", active!.PrimaryText);
+        Assert.Null(active.SecondaryText);
+        Assert.False(active.HasDual);
+    }
+
+    [Fact]
+    public void Gate291_DualSubtitleComposer_StylesSecondarySubtitle_WithSmallerFontToken()
+    {
+        var style = DualSubtitleComposer.DefaultSecondaryStyle;
+        Assert.True(style.FontScale < 1.0, "Secondary subtitle should be slightly smaller (e.g. 0.8x)");
+        Assert.False(string.IsNullOrEmpty(style.TextColorHex));
+    }
+
+    [Fact]
+    public void Gate292_AudioTrackSelector_SelectsPreferredLanguage()
+    {
+        var tracks = new List<MobileAudioTrack>
+        {
+            new(0, "ja", "Japanese (Original)"),
+            new(1, "en", "English (Dub)"),
+            new(2, "ko", "Korean (Dub)")
+        };
+
+        var selected = AudioTrackSelector.PickPreferredTrack(tracks, preferredLangCode: "ko");
+        Assert.NotNull(selected);
+        Assert.Equal(2, selected!.Index);
+        Assert.Equal("ko", selected.LanguageCode);
+
+        // Fallback to first if preferred not found
+        var fallback = AudioTrackSelector.PickPreferredTrack(tracks, preferredLangCode: "fr");
+        Assert.NotNull(fallback);
+        Assert.Equal(0, fallback!.Index);
+    }
+}