Module push_delivery 

QOT push delivery helpers.

Functions

try_send_qot_push_with_metric

v1.4.106 codex 1140 F8: qot push 投递助手. channel full / closed → 记录 metric (qot_push_dropped_total + per-sub-type 桶) + warn log; 不再 silent 吞错. 替换原 let _ = push_tx.try_send(event) pattern.

try_send_qot_to_conn_with_metric

首推缓存直发到单连接的投递助手。