docs backend evidence maps map completion MC B2

MC-B2 correction storage

Status: LOCAL_DONE. Date: 2026-10-27. Base: 5db9765e plus this task. Time: ~25 minutes.

Delivered

• Append-only migration 000144_station_corrections.sql:
  • station_corrections with station/account/field, structured JSONB value, optional note/evidence/coarse proximity bucket, idempotency key, the eight frozen statuses, reason codes and timestamps;
  • unique (account_id, client_submission_id) and a partial unique index enforcing one open correction per account+station+field;
  • queue/owner/pending indexes for bounded review and owner reads;
  • station_correction_decisions with append-only audit fields (decision, mandatory reason, decider kind/id, evidence JSONB, timestamp);
  • check constraints coupling open statuses to decided_at.
• sqlc.yaml directory schema includes 000144; sqlc generate produced the typed models and queries (create/get/by-key/owned/count/open/cancel/pending/ decide/decision).
• No official/ANP fact is updated by these tables.

Verification

• cd backend && sqlc diff empty; sqlc generate clean.
• go build ./... exit 0.
• git diff --check clean.
• Integration coverage for the migration and constraints is in MC-B4.