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

Log field, metric, action and event names now say what they count
and, for timings, the unit. Package internal/waf is internal/coreruleset.

Model: opus-5-5

internal/config/config_test.go

@@ -160,7 +160,7 @@ func loggedAnomalyDefaults() map[string]string {
 // defaultAlertEvents is the default of SWW_ALERT_EVENTS, and
 // defaultAlertCooldown that of SWW_ALERT_COOLDOWN.
 const (
-	defaultAlertEvents = "ban,permanent_ban,waf_block,anomaly,reputation_hit," +
+	defaultAlertEvents = "ban,permanent_ban,core_rule_set_match,anomaly,reputation_hit," +
 		"source_failure,file_error"
 	defaultAlertCooldown = "15m"
 )