Request tags, with refusing and limits per tag (closes #175)

Each request gets tags, logged as `tags`: `asn=`, `country=`, one per `SWW_TAG_LISTS` list holding the client, `crowdsec`, `dnsbl=<zone>`, `abuseipdb` and `exploitsignature`. `SWW_TAG_DENY` refuses by tag and `SWW_TAG_LIMIT_PERCENT` lowers limits by tag. They replace `SWW_ASN_LIMIT_PERCENT`, `SWW_COUNTRY_LIMIT_PERCENT` and `SWW_DENIED_COUNTRIES`, with no aliases. A tag in those settings that nothing configured can give stops the start.

Judgement call: `SWW_ASN_LIMIT_PERCENT_URL` stays, its entries counting like `asn=` tags.
Judgement call: `SWW_TAG_LIMIT_PERCENT` also lowers byte limits, as the settings it replaces did.
Trips a reader: `sww_country_list_refusals_total` now counts only `SWW_EXCLUSIVELY_ALLOWED_COUNTRIES` refusals.

Model: opus-5-5

internal/discriminator/coreruleset_test.go

@@ -61,6 +61,41 @@ func wantWAF(t *testing.T, line logLine, score *int, ruleIDs ...int) {
 	}
 }
 
+func TestCoreRuleSetMatchAddsTheExploitSignatureTag(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		name   string
+		mode   string
+		status int
+		action string
+	}{
+		{block, block, http.StatusForbidden, requestlog.ActionWAFBlocked},
+		{detect, detect, http.StatusOK, requestlog.ActionForward},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			s, _, _ := startWithClock(t, "", map[string]string{wafMode: tc.mode})
+
+			wantTags(t, s.request(client, sqlInjection, tc.status, tc.action),
+				"exploitsignature")
+			wantTags(t, s.get(client, http.StatusOK, requestlog.ActionForward))
+		})
+	}
+}
+
+func TestDetectedAttackIsRefusedByTagDenyLast(t *testing.T) {
+	t.Parallel()
+
+	s, _, _ := startWithClock(t, "", map[string]string{
+		wafMode: detect, tagDeny: "exploitsignature",
+	})
+
+	line := s.request(client, sqlInjection, http.StatusForbidden, requestlog.ActionDenied)
+	wantHeuristic(t, line, "tag_deny", `{"tag": "exploitsignature"}`)
+}
+
 func TestCoreRuleSetRefusesAttacksInBlockModeAndOnlyLogsThemInDetectMode(t *testing.T) {
 	t.Parallel()