Statically link the VC runtime (/MT) so the DLL needs no VC++ redist

The injected coop_hook.dll links the dynamic CRT, so it failed to load into games
on machines without the matching VC++ redistributable -- a real field failure of
the core feature. It was deferred because SafetyHook + Zydis (linked into the DLL)
default to /MD, so a per-target /MT would mismatch.

Set CMAKE_MSVC_RUNTIME_LIBRARY to MultiThreaded[Debug] project-wide (CMP0091 NEW,
available at our 3.21 minimum). Every target -- the DLL, the vendored deps, the
host, tools, and tests, on both x64 and the x86 sub-build -- now shares one static
CRT, so there's no mismatch and the whole tool ships redist-free.

Verified: x64 + x86 full builds are clean; dumpbin shows coop_hook.dll and
coop_hook_x86.dll import only system DLLs (USER32/ole32/d3d11/KERNEL32) -- no
VCRUNTIME/MSVCP -- and the /MT test binaries run.

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

hook/CMakeLists.txt

@@ -43,6 +43,6 @@ else()
 	set_target_properties(coop_hook PROPERTIES OUTPUT_NAME "coop_hook")
 endif()
 
-# TODO(dist): statically link the VC runtime (/MT) so the DLL loads in games on
-# machines without the matching VC redist. Deferred until SafetyHook + Zydis are
-# also forced to a static CRT to avoid a /MT-vs-/MD mismatch.
+# The VC runtime is statically linked (/MT) project-wide (see CMAKE_MSVC_RUNTIME_LIBRARY in the top
+# CMakeLists), so this DLL -- and the SafetyHook/Zydis it links -- carry no VC++ redist dependency and
+# load into games on any machine.