Name log fields, metrics and the Core Rule Set package for what they are (closes #192)

The first half of the naming audit: names now say what they are. `internal/waf` is `internal/coreruleset`. Log fields, the action `blocked_by_core_rule_set`, the metric and the alert event say Core Rule Set. Timings end `_ms`. Percentages say of what, as `rate_limit_percent` and `bytes_limit_percent`. Setting names follow in #234.

Judgement call: `blocked_by_core_rule_set`, not the audit's `core_rule_set_blocked`, to match `blocked_by_block_rule`.
Trips a reader: an existing state file holding `waf_blocked` or the anomaly scope `watch` stops the start and must be removed. `SWW_ALERT_EVENTS` listing `waf_block` must list `core_rule_set_match`.

Model: opus-5-5

internal/discriminator/metrics_test.go

@@ -32,7 +32,7 @@ func TestMetricsAreOffWhileTheTokenIsUnset(t *testing.T) {
 
 	// An empty token does not match the unset one either.
 	for _, authorization := range []string{bearer, "Bearer ", ""} {
-		s.adminRequest(authorization, http.MethodGet, discriminator.MetricsPath, "",
+		s.ownEndpointRequest(authorization, http.MethodGet, discriminator.MetricsPath, "",
 			http.StatusNotFound)
 	}
 }
@@ -60,7 +60,7 @@ func TestMetricsNeedTheTokenAndOtherPathsAreNotFound(t *testing.T) {
 		{http.MethodGet, "/_sww/bans", bearer, http.StatusNotFound},
 		{http.MethodPost, discriminator.HealthPath, "", http.StatusNotFound},
 	} {
-		got := s.adminRequest(tc.authorization, tc.method, tc.path, "", tc.status)
+		got := s.ownEndpointRequest(tc.authorization, tc.method, tc.path, "", tc.status)
 
 		if tc.status == http.StatusUnauthorized &&
 			got.header.Get("WWW-Authenticate") != "Bearer" {
@@ -91,7 +91,7 @@ func TestMetricsCountTheTraffic(t *testing.T) {
 	out.endedLines(t, 2)
 
 	forward := `{action="forward",instance="app",status_class="2xx"}`
-	notFound := `{action="admin",instance="app",status_class="4xx"}`
+	notFound := `{action="own_endpoint",instance="app",status_class="4xx"}`
 
 	// The request for the metrics is itself under way.
 	metrics := scrape(t, server.Addr)
@@ -347,7 +347,7 @@ func TestMetricsCountGeoJSRequestsAndFailures(t *testing.T) {
 
 	wantMetric(t, metrics, `sww_geojs_requests_total{instance="app"}`, 1)
 	wantMetric(t, metrics, `sww_geojs_failures_total{instance="app"}`, 1)
-	wantMetric(t, metrics, `sww_geojs_unanswered_total{instance="app"}`, 1)
+	wantMetric(t, metrics, `sww_requests_without_geojs_answer_total{instance="app"}`, 1)
 }
 
 // keptAnswer returns GeoJS's answer that the client at addr is in
@@ -381,8 +381,8 @@ func scrape(t *testing.T, addr string) string {
 func (s *sender) scrape() string {
 	s.t.Helper()
 
-	return string(s.adminRequest(bearer, http.MethodGet, discriminator.MetricsPath, "",
-		http.StatusOK).body)
+	return string(s.ownEndpointRequest(bearer, http.MethodGet, discriminator.MetricsPath,
+		"", http.StatusOK).body)
 }
 
 // metric returns the value of series in metrics, which are in the