Make the inline-hook (suspended-inject) Vulkan path work on Sphere Spectacle

The earlier validation concluded suspended-inject was "not applicable -- the
title requires launching through Steam." That was wrong; it was two bugs:

1. coop_vk_validate's inject mode launched the exe with CreateProcessW and a
   null working directory, so the game couldn't load steam_api64.dll / resources/
   (loaded relative to cwd) and never rendered -> no presents. Launch with the
   game's own folder as cwd and it runs fine directly, no Steam needed.
2. The game resolves vkQueuePresentKHR / vkCreateSwapchainKHR via
   vkGetInstanceProcAddr (volk's volkLoadInstance does this), but vk_hook only
   substituted our detours when they were resolved via vkGetDeviceProcAddr -- so
   the present bypassed the hook. Intercept those names in hk_vkGetInstanceProcAddr
   too (our detours already gate on g_capture_enabled/g_device, so handing them out
   before the device exists is safe).

With both fixed, inject mode captures Sphere Spectacle correctly: 1920x1080,
correct colors/orientation (screenshot), ~480 fps present while mirroring at the
~150 Hz throttle -- no present-thread impact (the VkCapture fix is shared).

Also makes the validator ASSERT a present-rate floor while capturing (it used to
report the rate and rationalize it, which is exactly what hid the 144->3 FPS
stall), and reports the true mirror rate from video.generation. Division of labor
is about who launches the game: layer for Steam-launched (can't suspend), inject
when we control the launch. README lessons-learned corrected accordingly.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

hook/src/vk_hook.cpp

@@ -271,6 +271,20 @@ VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL hk_vkGetInstanceProcAddr(VkInstance ins
 		{
 			return reinterpret_cast<PFN_vkVoidFunction>(&hk_vkGetDeviceProcAddr);
 		}
+		// vkGetInstanceProcAddr can also resolve device-level functions (the loader returns a
+		// dispatch trampoline). A game -- or volk's volkLoadInstance -- that resolves the present /
+		// swapchain entry points this way (rather than via vkGetDeviceProcAddr) would otherwise get
+		// the real loader pointer and bypass our capture. Sphere Spectacle does exactly this, so
+		// intercept them here too. (Our detours gate on g_capture_enabled / g_device, so handing them
+		// out before the device exists is safe.)
+		if (std::strcmp(name, "vkQueuePresentKHR") == 0)
+		{
+			return reinterpret_cast<PFN_vkVoidFunction>(&hk_vkQueuePresentKHR);
+		}
+		if (std::strcmp(name, "vkCreateSwapchainKHR") == 0)
+		{
+			return reinterpret_cast<PFN_vkVoidFunction>(&hk_vkCreateSwapchainKHR);
+		}
 	}
 	return real_gipa(instance, name);
 }