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/PacaVaultBackupRestoreGateTests.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using Paca.Mobile.Core;
+using Paca.Tests.Infrastructure;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+/// <summary>
+/// Gate 171 ~ 174: 기기 교체 및 무결성 보장을 위한 Paca Vault 스냅샷 백업 & 복원 엔진 기계적 검증
+/// </summary>
+public class PacaVaultBackupRestoreGateTests
+{
+    [Fact]
+    public void Gate171_VaultSnapshot_Creation_And_Integrity()
+    {
+        var favorites = new List<string> { "https://youtu.be/abc", "https://x.com/def" };
+        var queueUrls = new List<string> { "https://chzzk.naver.com/video/1" };
+
+        var snapshot = PacaVaultSnapshot.Create("device-alpha", favorites, queueUrls);
+
+        Assert.Equal("device-alpha", snapshot.SourceDeviceId);
+        Assert.Equal(2, snapshot.Favorites.Count);
+        Assert.Single(snapshot.QueueUrls);
+        Assert.True(snapshot.VerifyChecksum());
+
+        // 조작된 스냅샷 체크섬 검증 실패
+        var tampered = snapshot with { Favorites = new List<string> { "https://malicious.com" } };
+        Assert.False(tampered.VerifyChecksum());
+    }
+
+    [Fact]
+    public void Gate172_VaultSnapshot_Corrupted_ThrowsException()
+    {
+        var invalidJson = "{\"SourceDeviceId\":\"x\",\"Checksum\":\"invalid-hash\"}";
+
+        Assert.ThrowsAny<Exception>(() =>
+        {
+            var snapshot = JsonSerializer.Deserialize<PacaVaultSnapshot>(invalidJson);
+            if (snapshot == null || !snapshot.VerifyChecksum())
+            {
+                throw new InvalidDataException("Checksum verification failed");
+            }
+        });
+    }
+
+    [Fact]
+    public void Gate173_VaultRestorer_Merge_Strategy()
+    {
+        var currentFavorites = new List<string> { "https://youtu.be/1", "https://youtu.be/2" };
+        var backupFavorites = new List<string> { "https://youtu.be/2", "https://youtu.be/3" };
+
+        var merged = VaultRestorer.MergeLists(currentFavorites, backupFavorites);
+
+        // 중복 제거되어 1, 2, 3 총 3개 존재 확인
+        Assert.Equal(3, merged.Count);
+        Assert.Contains("https://youtu.be/1", merged);
+        Assert.Contains("https://youtu.be/2", merged);
+        Assert.Contains("https://youtu.be/3", merged);
+    }
+
+    [Fact]
+    public void Gate174_ServerHost_VaultEndpoints_Registered()
+    {
+        var serverHostPath = Path.Combine(SourceTree.Root, "src", "Paca.Server", "ServerHost.cs");
+        Assert.True(File.Exists(serverHostPath), "ServerHost.cs must exist");
+
+        var code = File.ReadAllText(serverHostPath);
+
+        Assert.Contains("/api/vault/backup", code);
+        Assert.Contains("/api/vault/restore", code);
+    }
+}