ZERO-STATIC Stage 3: the 16-bar stem cache goes live, behind ?stems=1

The heavy synthesis (CACHED = unitCost>=2.0: dx7 fleet, supersaw leads, juno60/vp330/hammond/... pads + their inserts) renders one chord-bar ahead in a Web Worker via the byte-exact stem-worker; bass/drums/stab/ sfx/found stay live.

• Deadline-miss ladder (ZERO-STATIC §4), failure = repetition never noise: a bar's stems late by t0-1s -> RUNG 1 vamp the previous bar's buffers (50ms seam)

DORMANT WHEN OFF — stem stays null unless opts.stems; every new branch keys off stemsOn (=stem&&healthy()), LOOKAHEAD stays classic, ensurePool is byte-identical without wantN.

• A/B, stationary heavy genres (the target case): awake cost ~halved (citypop 9.1->4.4), underruns better (0.94->0.19), layer RMS corr 0.998, sentinel 0, worker headroom 280-650x, all 92 genres' dx7 algs in…

▶ Play it: Neon Fiscal Year — parked on the genre this change names https://stellate.app/?genre=citypop&seed=6871&path=1530.6199,1549.6232,1511.6232&xdur=13.122

8bc625f https://github.com/aboard-io/stellate/commit/8bc625f7edb4f09a6e49d7cf63ac21cfb7136016