update_bleed_fixtures walked every interior source in the world four times per
doorway every frame (~1.0 ms/frame main thread, traced, Northshire at High).
Sources are now bucketed per placement once (same rows, same order, same sums:
another placement's claimant weighs 0), the evaluation runs at 10 Hz with
arrivals and dial changes bypassing the cadence, and the light is written only
on a real change. Captures inn-noon and perf-abbey-night are pixel-identical.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
