Name request log actions so they say what they mean (closes #229)

The request log's `action` values now say what they mean, as sneak named them: `request_header_too_large`, `client_is_rate_limited`, `blocked_by_block_rule` and `client_denied`, with no aliases. `banned` splits into `temporarily_banned` and `permanently_banned`, by whether the ban runs out. When a permanent ban also covers a client, that ban is the one reported.

Trips a reader: a request over a rate limit stays `client_is_rate_limited` even when the ban it makes is permanent.
Disclosure: the offence key `rule_blocked` is renamed in `clients.json` too, so an existing file holding it stops the start and must be removed. Its `version` stays 1.

Model: opus-5-5

internal/discriminator/refusallimit.go

@@ -28,7 +28,7 @@ func (refusalLimit) check(_ context.Context, rq *request, now time.Time) *verdic
 		return nil
 	}
 
-	if !rq.attack && !rq.ruleBlocked && !rq.wafBlocked {
+	if !rq.attack && !rq.blockedByBlockRule && !rq.wafBlocked {
 		return nil
 	}
 
@@ -42,13 +42,13 @@ func (refusalLimit) check(_ context.Context, rq *request, now time.Time) *verdic
 	status := rq.out.status
 
 	switch rq.line.WouldAction {
-	case requestlog.ActionRuleBlocked, requestlog.ActionWAFBlocked:
+	case requestlog.ActionBlockedByBlockRule, requestlog.ActionWAFBlocked:
 		status = http.StatusForbidden
-	case requestlog.ActionBanned:
+	case requestlog.ActionTemporarilyBanned, requestlog.ActionPermanentlyBanned:
 		status = cfg.BanResponse
 	}
 
 	rq.banForLimit(now, hit, status)
 
-	return &verdict{action: requestlog.ActionBanned, figures: limitFigures(hit)}
+	return &verdict{figures: limitFigures(hit)}
 }