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

tests/Paca.Tests/Mobile/MobileMediaIntegrityGateTests.cs

@@ -0,0 +1,82 @@
+using System;
+using System.IO;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading.Tasks;
+using Paca.Mobile.Core;
+using Xunit;
+
+namespace Paca.Tests.Mobile;
+
+/// <summary>
+/// 모바일 미디어 라이브러리 고속 무결성 검증 및 포맷 헤더 분석 게이트 (Gate 191 ~ Gate 194)
+/// </summary>
+public class MobileMediaIntegrityGateTests
+{
+    [Fact]
+    public void Gate191_ValidateMediaHeader_Mp4_FtypBox_Audit()
+    {
+        // MP4 컨테이너: 0~3 offset box size, 4~7 offset 'ftyp'
+        var mp4ValidHeader = new byte[] { 0x00, 0x00, 0x00, 0x20, 0x66, 0x74, 0x79, 0x70, 0x69, 0x73, 0x6F, 0x6D };
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(mp4ValidHeader, ".mp4"));
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(mp4ValidHeader, "video.m4a"));
+
+        var invalidHeader = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x41, 0x42, 0x43, 0x44 };
+        Assert.False(MediaIntegrityVerifier.ValidateMediaHeader(invalidHeader, ".mp4"));
+    }
+
+    [Fact]
+    public void Gate192_ValidateMediaHeader_Webm_Ebml_Audit()
+    {
+        // WebM / MKV EBML Header: 0x1A, 0x45, 0xDF, 0xA3
+        var webmHeader = new byte[] { 0x1A, 0x45, 0xDF, 0xA3, 0x9F, 0x42, 0x86, 0x81 };
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(webmHeader, ".webm"));
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(webmHeader, "sample.mkv"));
+
+        var corruptedHeader = new byte[] { 0x1A, 0x45, 0x00, 0x00 };
+        Assert.False(MediaIntegrityVerifier.ValidateMediaHeader(corruptedHeader, ".webm"));
+    }
+
+    [Fact]
+    public void Gate193_ValidateMediaHeader_Mp3_Id3_And_FrameSync_Audit()
+    {
+        // MP3 ID3v2: 'ID3' (0x49, 0x44, 0x33)
+        var id3Header = new byte[] { 0x49, 0x44, 0x33, 0x04, 0x00, 0x00, 0x00, 0x00 };
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(id3Header, ".mp3"));
+
+        // MP3 Sync Word: 0xFF, 0xFB
+        var syncHeader = new byte[] { 0xFF, 0xFB, 0x90, 0x64 };
+        Assert.True(MediaIntegrityVerifier.ValidateMediaHeader(syncHeader, ".mp3"));
+
+        var badMp3 = new byte[] { 0x00, 0x11, 0x22, 0x33 };
+        Assert.False(MediaIntegrityVerifier.ValidateMediaHeader(badMp3, ".mp3"));
+    }
+
+    [Fact]
+    public void Gate194_InspectIntegrity_FullPayload_Audit()
+    {
+        // 유효한 mp4 가짜 데이터 생성
+        var mp4Data = new byte[64];
+        mp4Data[4] = 0x66; mp4Data[5] = 0x74; mp4Data[6] = 0x79; mp4Data[7] = 0x70; // ftyp
+        var actualHash = Convert.ToHexString(SHA256.HashData(mp4Data)).ToLowerInvariant();
+
+        // 1. 체크섬 일치 및 헤더 유효
+        var okResult = MediaIntegrityVerifier.InspectIntegrity(mp4Data, "sample.mp4", actualHash);
+        Assert.True(okResult.IsValid);
+        Assert.True(okResult.ChecksumMatch);
+        Assert.Equal("mp4", okResult.Format);
+        Assert.Null(okResult.ErrorReason);
+
+        // 2. 체크섬 불일치
+        var mismatchResult = MediaIntegrityVerifier.InspectIntegrity(mp4Data, "sample.mp4", "0000000000000000000000000000000000000000000000000000000000000000");
+        Assert.False(mismatchResult.IsValid);
+        Assert.False(mismatchResult.ChecksumMatch);
+        Assert.Contains("체크섬", mismatchResult.ErrorReason);
+
+        // 3. 헤더 손상
+        var corruptedData = new byte[64]; // all zeros
+        var corruptResult = MediaIntegrityVerifier.InspectIntegrity(corruptedData, "sample.mp4");
+        Assert.False(corruptResult.IsValid);
+        Assert.Contains("헤더", corruptResult.ErrorReason);
+    }
+}