初版功能完成

internal/platform/windows/dpapi/dpapi_other.go

@@ -0,0 +1,12 @@
+//go:build !windows
+
+package dpapi
+
+import "errors"
+
+var ErrWindowsRequired = errors.New("DPAPI requires Windows")
+
+type Protector struct{}
+
+func (Protector) Protect([]byte) ([]byte, error)   { return nil, ErrWindowsRequired }
+func (Protector) Unprotect([]byte) ([]byte, error) { return nil, ErrWindowsRequired }