013 void event chaining

// Test: Parser should handle void event chaining
// Void events (no output branches) should support continuation syntax
// ~void-event() |> next_event() should create a continuation

~event void-event {}

~event another-void {}

// This should parse as a flow with ONE continuation
// Initial invocation: void-event()
// Continuation: |> another-void() (no branch specifier needed)
~void-event() |> another-void()