handle_repl_config_push now sends a ReplConfigPushReply{accepted,term}
from every exit path instead of silently dropping on the four reject
conditions (malformed request, missing bytes/sha256, sha256 mismatch,
conf_save_config failure). Term is sourced live from c->ha.term.
-EAGAIN activation-defer still replies accepted=1, unchanged.
Adds an XCE_TESTING-only send-hook mirroring ha_wal_ack_send_hook so
tests can observe the reply payload without a live endpoint.
Rongsong Shen
b7828eed4a