Kill the zombie worklets: destroy-on-retire, cap 8, voice sleep/wake

Paul's desktop clicks, root-caused: audio-thread render-budget exhaustion from worklets that NEVER STOP COMPUTING. Three mechanisms:

• 1. ZOMBIES (the big one): retirePool only DISCONNECTED nodes — a Faust worklet whose process() returns true keeps computing after disconnection, forever, per spec.

• The regime, layered: destroy-on-retire kills zombies at the source; an idle reaper tears down off-genre pools after 16 bars (<=3/bar at bar boundaries)

• The proof: the identical 29-station tour that drove eco-mode to level 3 by station 18 (load dips 0.85, heap 22->95MB, clicks rising) now runs load 1.000 flat, eco 0, clicks 0.1, 0 errors, node curve…

• Meter upgraded: "1.00x 8:8/8" = load, computing:resident/cap — Paul's 2-3-active observation is now literally the first number.

Verified: BEFORE/FINAL curves; cap-pin@8 torture (24 harvests, music voiced 11/11, revisit identical); cap8 tour returns to <=8 idle; standing single-genre soak sample-equal to baseline

▶ Play it: Cretaceous Vespers — parked on the genre this change names https://stellate.app/?genre=dinosynth&seed=2671&path=289.13871,308.13904,270.13904&xdur=13.122

ce74176 https://github.com/aboard-io/stellate/commit/ce74176f001a18b4bfb936bff18e0ec227c9f637