Response dispatch

Outputs subscribe to the bus independently. Each output is a ReactiveOutput that pattern-matches ReactionKind and consults its row of the per-output toggle matrix before firing. A reaction with LED + sound enabled and flash off produces a pulse and a clip and nothing on screen. The matrix is a hard gate, not a hint.

Each output independently subscribes to the bus via bus.subscribe(), which returns a fresh AsyncStream<FiredReaction>. The consumer loop reads a live config snapshot on every reaction and gates by: the output's master enable, the per-output per-reaction toggle matrix, and an internal playback-ends-at guard that prevents overlapping responses.

      Output consumer loop (same structure for all four outputs)

Output	Config type	Action	Notes
AudioPlayer	AudioOutputConfig	Plays the pre-selected fired.soundURL on each enabled Core Audio device. Volume = volumeMin + intensity * range.	For non-impact reactions, soundURL is nil. audio skips.
ScreenFlash	FlashOutputConfig	Renders a borderless NSWindow overlay per enabled screen: radial gradient + face image. Fade-in / hold / fade-out envelope, timing scaled to intensity.	Window pool reused across reactions. Face pulled from fired.faceIndices.
LEDFlash	LEDOutputConfig	PWM-dithers the Caps Lock LED via IOKit HID at 60 Hz. Optionally animates keyboard backlight via KeyboardBrightnessClient (CoreBrightness private framework) with a spring oscillation envelope. Restores both to pre-pulse state on completion.	Crash-recovery sentinel file written before first pulse; deleted on clean restore.
NotificationResponder	NotificationOutputConfig	Posts a UNMutableNotificationContent with a tier-matched phrase from a 40-locale string table. Auto-dismisses after dismissAfter.	Locale: user override or system fallback.

MenuBarFace also subscribes to the bus independently. It only reacts to .impact reactions, swaps the NSStatusItem icon to the face at fired.faceIndices[0] for max(0.5, debounce) seconds, then restores the template icon. It is not an output in the sense of the four above. it has no config provider and no toggle matrix.