Apply clang-format across the whole tree

Run clang-format (the repo's .clang-format: LLVM base, 120 cols, tabs,
Allman functions) over every source file so the tree is formatter-clean.
Whitespace only -- no behavior change; full x64 + x86 suites pass.

Also set SortIncludes: false in .clang-format. Windows include order is
load-bearing (windows.h must precede tlhelp32.h / mmreg.h / xinput.h /
dinput.h; winsock2.h must precede windows.h), and the default
alphabetical sort reorders tlhelp32.h ahead of windows.h -- a build
break. Leaving order alone keeps the manual, correct grouping.

tests/present_overhead.hpp

@@ -10,8 +10,7 @@
 
 #include <windows.h>
 
-namespace cooptest
-{
+namespace cooptest {
 inline double now_ms()
 {
 	LARGE_INTEGER f, c;
@@ -28,8 +27,7 @@ double avg_present_ms(int n, RenderFn render, PresentFn present)
 	render();
 	present(); // warm (first present/resource setup)
 	double total = 0;
-	for (int i = 0; i < n; ++i)
-	{
+	for (int i = 0; i < n; ++i) {
 		render();
 		const double a = now_ms();
 		present();