_log_order_error_history(order_number, msg) writes to
logs/sync_errors_history.log via a dedicated RotatingFileHandler
(100MB × 12 backups). Logger is lazy-initialised and non-propagating
so it doesn't pollute the root logger.
Purpose: orders.error_message is overwritten when a retry succeeds,
so the history log preserves permanent audit of every malformed-order
event regardless of later outcome. Helper never raises — callers are
already in a degraded path.
3 unit tests: append semantics, multi-order, exception isolation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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