US-001: coloane accounts (rar_test/prod_enabled, rar_creds_test/prod_enc,
rar_env_default) + submissions.rar_env; migrare cu backfill din ancora globala
AUTOPASS_RAR_ENV (creds->slot, enabled doar pe mediul cu creds) + recompute
idempotency_key env-aware (AUTO-FIX G + E4/3).
US-002: app/rar_env.py — medii_disponibile + rar_env_efectiv (REQ-DISP/DEFAULT).
US-003: build_key(account_id, canon, rar_env) — test vs prod = trimiteri distincte.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
