- New js/ui/PerimeterShimmer.js: constant amber base rim + glow, and two comets in counter-streams (amber CW, neon cyan CCW) tracing the cut-corner plate perimeter; pure arc math (perimeterPath / arcPoint / arcPolyline) exported for bare-Node tests
- QuestTrackerHud promotes READY rows to the console's cut-corner plate (CyberShape.rectPoints), drives PerimeterShimmer per-frame on the absolute clock so repaints never reset comet phase, and fires a one-shot rim flash when a row is claimed; shimmers are torn down with each paint
- data/quests.json gains tracker.shimmer config (enabled, notch, periodMs, dashFrac, phaseOffsetPerRow, claimFlashMs, base, comets)
- CyberShape.rectPoints added for absolute-coord cut-corner polygons
- New dev/perimeter-shimmer.test.mjs covering arc math, counter-streams, absolute-phase invariance, degenerate configs; quest-tracker tests extended for shimmer lifecycle and claim flash
