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/AudioPitchShiftEngineGateTests.cs

@@ -0,0 +1,64 @@
+using System;
+using Paca.Core;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+public class AudioPitchShiftEngineGateTests
+{
+    [Fact]
+    public void Gate385_AudioPitchShift_CalculatesAccuratePitchScale()
+    {
+        // 0 semitones -> 1.0
+        Assert.Equal(1.0, AudioPitchShiftEngine.CalculatePitchScale(0.0), 4);
+
+        // +12 semitones (1 octave up) -> 2.0
+        Assert.Equal(2.0, AudioPitchShiftEngine.CalculatePitchScale(12.0), 4);
+
+        // -12 semitones (1 octave down) -> 0.5
+        Assert.Equal(0.5, AudioPitchShiftEngine.CalculatePitchScale(-12.0), 4);
+
+        // +1 semitone -> ~1.0595
+        Assert.Equal(1.0595, AudioPitchShiftEngine.CalculatePitchScale(1.0), 4);
+    }
+
+    [Fact]
+    public void Gate386_AudioPitchShift_BuildsFfmpegFilterChain()
+    {
+        // +2 semitones (scale ~ 1.1225)
+        var filter = AudioPitchShiftEngine.BuildPitchShiftFilter(semitones: 2.0, sampleRate: 44100);
+
+        Assert.Contains("asetrate=", filter);
+        Assert.Contains("atempo=", filter);
+        Assert.Contains("aresample=44100", filter);
+    }
+
+    [Fact]
+    public void Gate387_AudioPitchShift_ClampsExtremeSemitoneRanges()
+    {
+        var clampedHigh = AudioPitchShiftEngine.ClampSemitones(24.0);
+        Assert.Equal(12.0, clampedHigh);
+
+        var clampedLow = AudioPitchShiftEngine.ClampSemitones(-30.0);
+        Assert.Equal(-12.0, clampedLow);
+    }
+
+    [Fact]
+    public void Gate388_AudioPitchShift_BuildsFullCommandLine_WithVideoCopy()
+    {
+        var cmd = AudioPitchShiftEngine.BuildPitchShiftCommandLine(
+            inputPath: "C:\\music\\karaoke.mp4",
+            outputPath: "C:\\music\\karaoke_plus1.mp4",
+            semitones: 1.0,
+            isAudioOnly: false,
+            sampleRate: 48000
+        );
+
+        Assert.Contains("-i \"C:\\music\\karaoke.mp4\"", cmd);
+        Assert.Contains("-c:v copy", cmd);
+        Assert.Contains("-filter:a \"asetrate=", cmd);
+        Assert.Contains("aresample=48000", cmd);
+        Assert.Contains("-c:a aac -b:a 192k", cmd);
+        Assert.EndsWith("\"C:\\music\\karaoke_plus1.mp4\" -y", cmd);
+    }
+}