Rename the settings whose names do not say what they control (closes #234)

Applies the setting renames of the naming audit under the SWW_WAF_ and
SWW_RPROXY_ prefixes, with sneak's names for the IP reputation cache
time and the two time limits, which now take milliseconds. The rproxy
log field default_disposition becomes waf_backend_no_answer, and
config.Config and config.FromEnvironment become config.WAF and
config.WAFFromEnvironment. Go fields, test names and prose follow. No
aliases; nothing reads the old names.

Model: opus-5-5

internal/rproxy/request.go

@@ -65,12 +65,13 @@ type request struct {
 	start       time.Time
 
 	// disposition is what is done with the request: waf's valid disposition,
-	// or SWW_RPROXY_DEFAULT_DISPOSITION. It is "" when neither gave one.
+	// or SWW_RPROXY_WAF_BACKEND_NO_ANSWER_DISPOSITION. It is "" when neither
+	// gave one.
 	disposition string
 	// answered is true when waf gave disposition, which makes a report due,
-	// and byDefault when SWW_RPROXY_DEFAULT_DISPOSITION did.
-	answered  bool
-	byDefault bool
+	// and wafNoAnswer when SWW_RPROXY_WAF_BACKEND_NO_ANSWER_DISPOSITION did.
+	answered    bool
+	wafNoAnswer bool
 	// asn and country are waf's X-Client-ASN and X-Client-Country, for the
 	// app.
 	asn, country string
@@ -454,7 +455,7 @@ func (rq *request) finish(ctx context.Context) {
 			),
 			DurationResponseMS: requestlog.Milliseconds(end.Sub(requestEnd)),
 			Disposition:        rq.disposition,
-			DefaultDisposition: rq.byDefault,
+			WAFBackendNoAnswer: rq.wafNoAnswer,
 		},
 	)
 	if err != nil {