feat: authenticate Windows command launcher and signal helper

internal/client/supervisor/windows/native_exec.go

@@ -33,7 +33,11 @@ var (
 // token/session selection and Job Object containment in the native build; the
 // test adapter uses the same shell and output limits without OS handles.
 type NativeOptions struct {
-	Shells           ShellPaths
+	Shells ShellPaths
+	// ExecutablePath is the canonical rvbox.exe path used for private
+	// per-command launcher mode. An empty value is resolved from the running
+	// service executable on Windows.
+	ExecutablePath   string
 	WorkRoot         string
 	JobProfiles      map[string]JobProfile
 	MaxWrapperBytes  uint64
@@ -87,6 +91,7 @@ type execProcess struct {
 	identity   supervisor.EffectiveIdentity
 	cmd        *exec.Cmd
 	pid        uint32
+	creation   uint64
 	stdin      io.WriteCloser
 	stdout     io.ReadCloser
 	stderr     io.ReadCloser
@@ -96,6 +101,7 @@ type execProcess struct {
 	waitFn     func() (int32, bool, error)
 	killFn     func(uint32) error
 	releaseFn  func() error
+	signalFn   func(context.Context) (bool, error)
 	snapshotFn func() (supervisor.ResourceSnapshot, error)
 
 	mu         sync.Mutex