refactor(windows): split Windows code into winapi (#575)

utils/winapi/winapi_windows.go

@@ -0,0 +1,45 @@
+//go:build windows
+
+// Package winapi centralizes low-level Windows API access used across
+// HackBrowserData. It exposes typed wrappers around specific syscalls
+// that golang.org/x/sys/windows does not cover, plus shared LazyDLL
+// handles and a small error-handling helper.
+//
+// Callers: utils/injector, filemanager, crypto. Higher-level Windows
+// browser utilities live in utils/winutil.
+package winapi
+
+import (
+	"errors"
+	"fmt"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+// Package-level LazyDLL handles. Declaring them once here avoids the
+// NewLazySystemDLL boilerplate previously spread across injector,
+// filemanager, and crypto.
+var (
+	Kernel32 = windows.NewLazySystemDLL("kernel32.dll")
+	Ntdll    = windows.NewLazySystemDLL("ntdll.dll")
+	Crypt32  = windows.NewLazySystemDLL("crypt32.dll")
+)
+
+// CallBoolErr wraps the common "r1 == 0 means failure" Win32 convention.
+// Win32 GetLastError often returns ERROR_SUCCESS (errno 0) even on failure,
+// so we distinguish the "no-errno" case explicitly to avoid emitting a
+// misleading "operation completed successfully" message. errors.As is
+// used instead of a type assertion so the check stays correct if
+// x/sys/windows ever wraps the underlying errno.
+func CallBoolErr(p *windows.LazyProc, args ...uintptr) (uintptr, error) {
+	r, _, callErr := p.Call(args...)
+	if r == 0 {
+		var errno syscall.Errno
+		if errors.As(callErr, &errno) && errno == 0 {
+			return 0, fmt.Errorf("%s: failed (no errno)", p.Name)
+		}
+		return 0, fmt.Errorf("%s: %w", p.Name, callErr)
+	}
+	return r, nil
+}