α + half-life calibration

E-M7-04 (Stream 1c): backfit the LP-norm concentration parameter α (PRD §6.6.2.5, default 0.65) and recency-decay half-lives (§6.2.9 / §6.6.2.4) against the seed-account ledger. Calibration math is deterministic; runs read real `verb_edges` + `score_records` rows.