feat/decision-plane
main
- packages/decision: erMatchDecision (0pt.er.pair_match mot siax-decision :4600) - comparePair async + borderline-band (±0.05 av review_threshold) → decision.match (D1 advisory) — deterministisk status GÄLLER om decision abstainar - OPT_DECISION_ER_ENABLED=1-gate (off tills kalibrering) - tests async-anpassade (await generateCandidates/rejects.toThrowError) - typecheck: 13 fel = pre-existing extraction-route (main-paritet), 0 nya fel - tester: 1108 passed | 184 skipped