The OpenRouter provider stashes the outgoing request BODY (never headers --
Authorization is built separately and build_body() copies only whitelisted
option keys) in the new PRAutoBlogger_Request_Recorder before dispatch;
Cost_Tracker::log_api_call() consumes it (consume-once) into
generation_log.request_json. All seven chat call sites covered with zero
call-site changes; error/timeout rows carry the request too. Retention
rides the existing prautoblogger_request_json_retention_days prune.
Unblocks M3 edit+rerun (stage inputs now exist) and makes the M2 dossier
raw-input trace real (QA seq 20 F1).
Agent-Session: engineer-prab-m3-20260612
