-- v1.0.7 item B (day 1): partial composite index for the reversal
-- worker's hot path.
--
-- The worker's select per tick is:
--   SELECT * FROM seller_transfers
--    WHERE status = 'reversal_pending'
--      AND (next_retry_at IS NULL OR next_retry_at <= NOW())
--    ORDER BY next_retry_at NULLS FIRST
--    LIMIT 20;
--
-- Migration 116 already provides idx_seller_transfers_retry on
-- `(status, next_retry_at) WHERE status='failed' AND next_retry_at
-- IS NOT NULL` for TransferRetryWorker. That index cannot serve the
-- reversal worker's query because (a) the partial WHERE clause
-- excludes reversal_pending rows, and (b) it excludes rows with
-- next_retry_at NULL — which are exactly the freshly-inserted
-- reversal_pending rows the worker should pick up on first pass.
--
-- This migration adds a sibling partial index scoped to
-- reversal_pending, including NULL next_retry_at so the first-pass
-- rows land in the index.
--
-- Why not widen migration 116's existing index instead: widening a
-- partial index requires dropping and recreating it, which would
-- require a table-level lock. Two parallel partial indexes is the
-- cheaper DDL.
--
-- No state machine enforcement in this migration — the authoritative
-- transition matrix lives in
-- `internal/core/marketplace/transfer_transitions.go` and is exercised
-- by TestTransferStateTransitions. Day 2 routes call sites through
-- the matrix; day 3 exercises the end-to-end flow in a smoke probe.

CREATE INDEX IF NOT EXISTS idx_seller_transfers_reversal_pending
    ON seller_transfers(status, next_retry_at)
    WHERE status = 'reversal_pending';