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/SubtitleSyncDrifterGateTests.cs

@@ -0,0 +1,64 @@
+using System;
+using Paca.Mobile.Core;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+public class SubtitleSyncDrifterGateTests
+{
+    [Fact]
+    public void Gate433_SubtitleSyncDrifter_ShiftsConstantOffset_Accurately()
+    {
+        var srt = @"1
+00:01:20,000 --> 00:01:25,500
+Hello World";
+
+        var shifted = SubtitleSyncDrifter.ShiftOffsetSrt(srt, shiftSeconds: 2.5);
+
+        Assert.Contains("00:01:22,500 --> 00:01:28,000", shifted);
+        Assert.Contains("Hello World", shifted);
+    }
+
+    [Fact]
+    public void Gate434_SubtitleSyncDrifter_PreventsNegativeTimestamps()
+    {
+        var srt = @"1
+00:00:05,000 --> 00:00:08,000
+Early cue";
+
+        var shifted = SubtitleSyncDrifter.ShiftOffsetSrt(srt, shiftSeconds: -10.0);
+
+        Assert.Contains("00:00:00,000 --> 00:00:00,000", shifted);
+    }
+
+    [Fact]
+    public void Gate435_SubtitleSyncDrifter_RescalesTimeByFpsRatio()
+    {
+        var srt = @"1
+00:01:40,000 --> 00:01:50,000
+Pacing test"; // 100s to 110s
+
+        // Speedup by 10% (speed factor 1.10 -> duration scales by 1/1.10 = 0.90909)
+        var rescaled = SubtitleSyncDrifter.RescaleTimeSrt(srt, speedFactor: 1.10);
+
+        // 100 / 1.10 = 90.909s = 00:01:30,909
+        Assert.Contains("00:01:30,909", rescaled);
+    }
+
+    [Fact]
+    public void Gate436_SubtitleSyncDrifter_ResyncsByTwoAnchorPoints()
+    {
+        // Anchor 1: at 100s, video speech is at 105s (+5s)
+        // Anchor 2: at 1000s, video speech is at 1050s (+50s)
+        // m = (1050 - 105) / (1000 - 100) = 945 / 900 = 1.05
+        // b = 105 - (1.05 * 100) = 0
+        var srt = @"1
+00:08:20,000 --> 00:08:25,000
+Middle dialogue"; // 500s -> 500 * 1.05 = 525s = 00:08:45,000
+
+        var resynced = SubtitleSyncDrifter.ResyncByAnchorsSrt(srt, orig1: 100.0, target1: 105.0, orig2: 1000.0, target2: 1050.0);
+
+        Assert.Contains("00:08:45,000", resynced);
+        Assert.Contains("Middle dialogue", resynced);
+    }
+}