research: Study C FREEZE — maker inventory-lean pre-registration (follow arm verdict; fade failed its concentration gate)

score_lean wired into the nightly (walk-forward as-of screening, frozen
trigger, chain truth); params/study_lean.json frozen; forward window =
ledger rows dated after this commit. Fade $2k+ arm excluded by the
pre-declared gate (top event 32%, tail net-negative) — tracked
report-only. Follow $150-500: robust across 869 events (top 14%).

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

.gitignore

@@ -54,3 +54,4 @@ research/meta/
 research/.surge*.pull.*
 research/.oracle*.pull.*
 research/replay_out/
+research/.maker_lean_triggers.json