Sdl backend (#670)

* [audio] added sdl audio backend and in-tree atrac9 decoder

* [input] replaced per-platform pad readers with sdl gamepad input

* [video] added sdl window and host display plumbing

* [gui] added host display options and per-game render settings

* [bink] synced host movie playback to the guest audio clock

* [cpu] hooked windows write faults into guest image tracking

* [perf] added guest and render profiling, reserved host cpu lanes

* [kernel] fixed stale pthread mutex handle alias

* [host] wired the sdl session, save-data paths and project references

* [audio] hoisted ajm trace stackalloc out of its loop

* [video] Add guest image sync setting

* [build] Strip native symbols

* reuse

src/SharpEmu.HLE/GuestImageWriteTracker.cs

@@ -87,17 +87,14 @@ public static unsafe class GuestImageWriteTracker
 
     private static RangeSnapshot _rangeSnapshot = RangeSnapshot.Empty;
 
-    // Windows defaults off: VirtualProtect fault sync still regresses titles
-    // like Dead Cells / Demon's Souls. Opt in with SHARPEMU_GUEST_IMAGE_CPU_SYNC=1
-    // when a title needs CPU-written guest planes (e.g. GTA intro). Linux/macOS
-    // keep the historical opt-out (=0 disables).
+    // CPU-written guest image synchronization is the compatible default. A few
+    // titles (currently GTA V) require the lower-overhead watch-only path and
+    // opt out explicitly with SHARPEMU_GUEST_IMAGE_CPU_SYNC=0.
     private static readonly bool _enabled =
-        OperatingSystem.IsWindows()
-            ? string.Equals(
-                Environment.GetEnvironmentVariable("SHARPEMU_GUEST_IMAGE_CPU_SYNC"),
-                "1",
-                StringComparison.Ordinal)
-            : Environment.GetEnvironmentVariable("SHARPEMU_GUEST_IMAGE_CPU_SYNC") != "0";
+        !string.Equals(
+            Environment.GetEnvironmentVariable("SHARPEMU_GUEST_IMAGE_CPU_SYNC"),
+            "0",
+            StringComparison.Ordinal);
     private static readonly (bool Wildcard, ulong[] Addresses) _lifetimeTraceFilter =
         ParseAddressList(Environment.GetEnvironmentVariable("SHARPEMU_TRACE_GUEST_IMAGE_ADDRS"));
     private static readonly (bool Wildcard, string[] Sources) _lifetimeSourceTraceFilter =