c8d8df41d2
test_concurrent_dedup_persists_land_in_order clears os.environ, which drops the per-test HERMES_HOME; FeishuAdapter then resolves feishu_seen_message_ids.json under the operator's real ~/.hermes and every id a running gateway has persisted lands in writes[-1] (265 extra elements in the report). Keep HERMES_HOME through the wipe so the store stays in the sandbox. Slim redo of #110708 (same fix, without re-indenting the test body).