Fix Vulkan presenter synchronization and frame handling issues (#747)

* [VideoOut/Vulkan] Fix boot deadlock, writeback stall, and presentation bugs

- Presenter thread now starts on the compute dispatch path too, fixing
  a boot deadlock when a title's first GPU work is compute (Ghost of
  Yotei G-Buffer clear).
- Guest render-target format swaps between sibling pixel formats now
  reinterpret in place instead of recreating blank, preserving
  GPU-written content.
- Vectorized the guest-buffer writeback scan (equal-byte skip + coarse
  per-page pre-check), fixing multi-second stalls on fragmented buffers
  that starved JobWorker completion signals.
- _presentedSequence now advances on every Render() early-return path,
  fixing an unthrottled busy loop on stale/dropped presentations.

* Remove unnecessary Silk.NET.Windowing dependency

tests/SharpEmu.Libs.Tests/VideoOut/VulkanFormatConversionTests.cs

@@ -0,0 +1,56 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using Silk.NET.Vulkan;
+using SharpEmu.Libs.VideoOut;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.VideoOut;
+
+public sealed class VulkanFormatConversionTests
+{
+    [Theory]
+    [InlineData(Format.R8G8B8A8Unorm, Format.A2R10G10B10UnormPack32, true)]
+    [InlineData(Format.R8G8B8A8Unorm, Format.A2B10G10R10UnormPack32, true)]
+    [InlineData(Format.A2R10G10B10UnormPack32, Format.R8G8B8A8Unorm, true)]
+    [InlineData(Format.A2B10G10R10UnormPack32, Format.R8G8B8A8Unorm, true)]
+    public void RequiresRealFormatConversion_FlagsTheBitIncompatiblePair(
+        Format from,
+        Format to,
+        bool expected)
+    {
+        Assert.Equal(expected, VulkanVideoPresenter.RequiresRealFormatConversion(from, to));
+    }
+
+    [Theory]
+    [InlineData(Format.R8G8B8A8Unorm, Format.B8G8R8A8Unorm)]
+    [InlineData(Format.R8G8B8A8Unorm, Format.R8G8B8A8Srgb)]
+    [InlineData(Format.R8G8B8A8Unorm, Format.R8G8B8A8Unorm)]
+    [InlineData(Format.A2R10G10B10UnormPack32, Format.A2B10G10R10UnormPack32)]
+    [InlineData(Format.R16G16B16A16Sfloat, Format.R32G32Sfloat)]
+    public void RequiresRealFormatConversion_LeavesEveryOtherPairAlone(Format from, Format to)
+    {
+        Assert.False(VulkanVideoPresenter.RequiresRealFormatConversion(from, to));
+    }
+
+    [Fact]
+    public void BitCastOfOpaqueBlackRgba8AsA2r10g10b10_ProducesTheObservedRed()
+    {
+        const uint opaqueBlackRgba8 = 0xFF000000u; // bytes 00 00 00 FF, little-endian
+
+        var alpha2Bit = (opaqueBlackRgba8 >> 30) & 0x3u;
+        var red10Bit = (opaqueBlackRgba8 >> 20) & 0x3FFu;
+        var green10Bit = (opaqueBlackRgba8 >> 10) & 0x3FFu;
+        var blue10Bit = opaqueBlackRgba8 & 0x3FFu;
+
+        Assert.Equal(3u, alpha2Bit);
+        Assert.Equal(1008u, red10Bit);
+        Assert.Equal(0u, green10Bit);
+        Assert.Equal(0u, blue10Bit);
+
+        var redAsFloat = red10Bit / 1023.0;
+        Assert.True(
+            Math.Abs(redAsFloat - 0.9853372434443793) < 0.0001,
+            $"expected ~0.9853 (matches the red observed live), got {redAsFloat}");
+    }
+}