servewaf answers rproxy's question about each request and takes its report (closes #170)

`smallwebwaf servewaf` runs today's checks on the visitor's request each
question carries, answers rproxy, and passes nothing to an app. rproxy reports
every request servewaf answered. A report counts an allowed request's bytes and
writes servewaf's second log line. The table holds a copy of what a report
needs, never the request, so a report cannot reach a request being handled.

Judgement call: a question's body is read before any check; over 64 KiB gets 400.
Judgement call: a report's bytes and durations have ceilings, so they cannot overflow.
Judgement call: a `close` disposition for SWWAF_BAN_RESPONSE=close.

Model: opus-5-5

internal/proxy/reputation.go

@@ -110,6 +110,7 @@ func (rq *request) noteHit(hit bans.ReputationHit, reason string) {
 	rq.h.metrics.ReputationHit(hit.Source)
 	rq.h.alerts.Raise(alerts.Alert{
 		Event:    alerts.EventReputationHit,
+		Host:     rq.site,
 		Client:   rq.client,
 		Netblock: rq.h.clientGroup(rq.client),
 		ASN:      rq.line.ASN,