Refine platform detection (unsigned Xbox 360)

Use FastFileInfo.Platform to better distinguish unsigned Xbox 360 FastFiles from PS3 by treating OpenedFastFileHeader.Platform == "Xbox 360" as Xbox360 in IsXbox360. Add a Platform string property to FastFileHeader (with docs and default empty string) and initialize it from info.Platform, and update the exposed Platform mapping to rely on IsXbox360. This enables accurate detection for unsigned console files (e.g. converter output or unsigned MW2 Xbox 360) where header bytes alone look like PS3 but zone-peek identification is available.

Author: primetime43

Call of Duty FastFile Editor/Models/FastFile.cs

@@ -43,7 +43,10 @@ public class FastFile
         /// </summary>
         public bool IsXbox360 => !IsPC && !IsWii && !IsGhostsFile && (
             OpenedFastFileHeader.IsSigned ||
-            OpenedFastFileHeader.GameVersion == FastFileLib.GameDefinitions.MW2Definition.DevBuildVersionValue);
+            OpenedFastFileHeader.GameVersion == FastFileLib.GameDefinitions.MW2Definition.DevBuildVersionValue ||
+            // Unsigned Xbox 360 (e.g. converter output, unsigned MW2 Xbox 360): the header
+            // looks identical to PS3, but FastFileInfo's zone peek positively identified it.
+            OpenedFastFileHeader.Platform == "Xbox 360");
 
         /// <summary>
         /// Indicates if this FastFile is from a PC version.
@@ -73,7 +76,7 @@ public bool IsWii
         public string Platform => IsPC ? "PC"
                                 : IsWii ? "Wii"
                                 : IsGhostsFile ? "PS3"  // Ghosts is signed on PS3 retail; no Xbox 360 samples tested yet
-                                : OpenedFastFileHeader.IsSigned ? "Xbox 360"
+                                : IsXbox360 ? "Xbox 360"  // signed, dev-build, or zone-peek-confirmed unsigned Xbox 360
                                 : "PS3";
 
         /// <summary>
@@ -222,6 +225,15 @@ public class FastFileHeader
             /// </summary>
             public bool IsWii { get; private set; }
 
+            /// <summary>
+            /// Refined platform string from <see cref="FastFileInfo.FromFile"/> — for unsigned
+            /// big-endian console FFs this is the result of peeking the decompressed zone
+            /// (WaW MemAlloc1 magic / MW2 header layout) to split PS3 from Xbox 360, rather
+            /// than the header-only "PS3/Xbox 360". Empty for zone-loaded FastFiles. Values:
+            /// "PS3", "Xbox 360", "PC", "Wii", or "PS3/Xbox 360" when genuinely undecidable.
+            /// </summary>
+            public string Platform { get; private set; } = "";
+
             public FastFileHeader(string filePath)
             {
                 // Single source of truth: delegate to FastFileLib.FastFileInfo so detection
@@ -245,6 +257,7 @@ public FastFileHeader(string filePath)
                 IsSigned = info.IsSigned;
                 IsPC = info.IsPC;
                 IsWii = info.IsWii;
+                Platform = info.Platform ?? "";
 
                 switch (info.GameVersion)
                 {