const DEFAULT_DROPPED_FRAME_MS: 25
Where a frame stops being jitter, for a caller that supplies no budget.
A named mirror of DROPPED_FRAME_MS in apps/game/src/engine/perfBudgets.ts,
which layer order forbids importing — packages/devtools is layer 6 and
apps/ is above it. A bare ?? 25 four lines under a docstring saying the
number is not defaulted here is the "one constant instead of two that must
agree" shape, leaving the smaller twin unnamed and unfindable. Every browser
caller passes TimingPort.droppedFrameMs; the headless runner passes this,
by name, so a grep for one finds the other.