feat: strengthen P0 security and operations

Tiku.Application/Assets/IAssetSecurityScanner.cs

@@ -0,0 +1,30 @@
+namespace Tiku.Application.Assets;
+
+public enum AssetSecurityScanVerdict
+{
+    Clean,
+    Infected
+}
+
+public sealed record AssetSecurityScanResult(
+    AssetSecurityScanVerdict Verdict,
+    string Provider,
+    string? Signature,
+    long BytesScanned,
+    string RawResponse);
+
+public interface IAssetSecurityScanner
+{
+    Task<AssetSecurityScanResult> ScanAsync(
+        Stream content,
+        long? declaredLength,
+        CancellationToken cancellationToken = default);
+
+    Task<bool> CheckHealthAsync(CancellationToken cancellationToken = default);
+}
+
+public sealed class AssetSecurityScannerException(string code, string message, Exception? innerException = null)
+    : Exception(message, innerException)
+{
+    public string Code { get; } = code;
+}