Nothing arrives unannounced: the horde gets its breather, the boss gets a name

THEY KEEP COMING is a 2.4s 'over' beat again (warnHorde in beats.js) instead of a
flash raised on the same frame the wave lands, and the chapter boss walks on behind
an overlay — his name in red over ENTERED THE COURT — held for 3s by the new
self-dismissing modal clock (m.hold) rather than announced on a routine-set card.

startHorde returns a bool: if the court has been taken when the warning expires the
pendingHorde latch is re-armed rather than the set losing the horde it paid for. The
warning ticks on its own clock, not on the 'over' beat, so a beat that moves the
phase underneath it can't strand it (the mgT lock, again).

Three tests, 15 total.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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