Remove the CrowdSec decision feed (closes #315)

sneak ruled to remove it. Gone: the heuristic crowdsec, the ban cause
crowdsec and its earlier_bans count, the tag crowdsec, the settings
SWW_WAF_CROWDSEC_LAPI_URL and SWW_WAF_CROWDSEC_LAPI_KEY, the decision
list fetch and parse in internal/reputation, their tests, and every
mention in the README, SPEC.md and docs/. EVALUATION.md keeps its
comparison of tools.

The ban ledger's internal ban function loses its expires parameter,
which only CrowdSec bans used.

Model: opus-5-5

internal/waf/answertime_test.go

@@ -48,9 +48,6 @@ const (
 	silentAbuseIPDBURL = "silent://abuseipdb/api/v2/check"
 	// wholeLimit is the percentage of a rate limit that lowers it not at all.
 	wholeLimit = 100
-	// clientsDecision is the CrowdSec decision list holding client alone.
-	clientsDecision = `[{"duration": "4h0m0s", "scenario": "crowdsecurity/ssh-bf", ` +
-		`"scope": "Ip", "type": "ban", "value": "` + client + `"}]`
 )
 
 // cookies returns a Cookie header's value with count cookies.
@@ -296,10 +293,6 @@ func TestTheHeaderLimitsComeBeforeEveryCheckThatRefuses(t *testing.T) {
 			"/", leaveAsItIs,
 		},
 		{"a blocklist", map[string]string{blocklistURLs: dropURL}, "/", listClient},
-		{
-			"the CrowdSec decision list",
-			map[string]string{crowdSecURL: lapi, crowdSecKey: bouncerKey}, "/", decideOnClient,
-		},
 		{
 			"a DNS blocklist", map[string]string{
 				dnsblZones: dnsblZone, dnsblResolver: noResolver, dnsblAbuseIPDBAction: actionDeny,
@@ -592,12 +585,6 @@ func listClient(t *testing.T, server *waf.Server, now time.Time) {
 	}
 }
 
-// decideOnClient puts client on the CrowdSec decision list.
-func decideOnClient(t *testing.T, server *waf.Server, now time.Time) {
-	t.Helper()
-	loadDecisions(t, server, now, clientsDecision)
-}
-
 // leaveAsItIs prepares nothing.
 func leaveAsItIs(*testing.T, *waf.Server, time.Time) {}
 
@@ -641,12 +628,6 @@ func TestARefusedRequestDoesNotWaitForASlowGeoJS(t *testing.T) {
 			name: "a blocklist", env: map[string]string{blocklistURLs: dropURL},
 			prepare: listClient, status: forbidden, action: requestlog.ActionClientDenied,
 		},
-		{
-			name:    "the CrowdSec decision list",
-			env:     map[string]string{crowdSecURL: lapi, crowdSecKey: bouncerKey},
-			prepare: decideOnClient, status: forbidden,
-			action: requestlog.ActionTemporarilyBanned,
-		},
 		{
 			name: "the header limits", cookie: cookies(cookieLimit + 1),
 			prepare: leaveAsItIs, status: tooLarge,
@@ -774,7 +755,6 @@ func TestWAFAnswersWithinTheTimeLimitWhileEveryOutsideSourceHangs(
 		dnsblZones: dnsblZone, dnsblResolver: resolver,
 		abuseIPDBKey:  accountKey,
 		blocklistURLs: held + "/drop.txt", asnLimitPercentURL: held + "/asn.txt",
-		crowdSecURL: held, crowdSecKey: bouncerKey,
 	})
 
 	// The lists are fetched outside the synctest bubble below: a wait on the