Signals

One power announces something by name, and any power listening for that name reacts. Signals let separately written origins work together without knowing each other's power ids.

Send with emit_signal. Listen with action_on_signal.

• The sender never hears its own signals, even with *.
• Signals are instant. A listener that isn't loaded at that moment misses it.
• A listener's actions can send signals, up to 8 levels deep. Deeper signals are dropped and logged, so two powers can't set each other off forever.