feat: complete Windows client control and recovery paths

internal/client/windowstray/service_other.go

@@ -0,0 +1,20 @@
+//go:build !windows
+
+package windowstray
+
+import (
+	"context"
+	"errors"
+	"io"
+)
+
+var ErrUnsupported = errors.New("Windows tray IPC is unavailable on this platform")
+
+// Serve exists on every platform so the service wiring stays build-tag
+// neutral.  Unix-like client support is deferred in v1; this endpoint must
+// never silently become a second client daemon.
+func Serve(context.Context, Handler) error { return ErrUnsupported }
+
+func Request(context.Context, Frame) (Frame, error) { return Frame{}, ErrUnsupported }
+
+func Run(context.Context, io.Writer) error { return ErrUnsupported }