Clean-sky modal chrome; audio survives background tabs

sky shows brand + three chips (play/stop, chyron, controls); panel and lower-third are modals (backdrop/Esc/chip dismiss)

• lookahead 4->6s vs background timer clamp; visibility/focus resume handlers; audited: nothing in the audio path depends on rAF

▶ Play it: Highway Heat Death — where the synthesis is the identity, not the decoration https://stellate.app/?genre=synthwave&seed=9793&path=859.9909,878.9942,840.9942&xdur=13.122

efc2470 https://github.com/aboard-io/stellate/commit/efc2470961a29ad4abcc84b1fe14207e05e16ffd