Review P4: emissive_boost now lifts only above a 0.6 knee (equal to the old
gain at 1.0), so additive spells and lava keep their look and the excess feeds
the bloom. Review P3: the window gain applies to static_gx's SIDN light term
before fog, not to the whole fogged batch. Review P6: Low-tier extract taps
scale with the quarter-size target. Review P7: excess capped at 64 (no NaN).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
