Rename the program to sww and its deciding daemon to discriminator

The program is now sww, built from cmd/sww, with two modes: sww rproxy and
sww discriminator. servewaf becomes discriminator everywhere it names that
daemon: the package (internal/discriminator), its types, functions, files, the
discriminator_line log field, and its docs and tests.

smallwebwaf is left only where sneak's directive allows it: the documents'
product name, the git.eeqj.de/sneak/smallwebwaf URLs, and the Go module path
sneak.berlin/go/smallwebwaf. Everywhere else a name containing it takes the sww
form: the package (internal/sww), metric names (sww_*), the X-Sww-* headers,
the /_sww/ admin endpoints, the SWW_COMMAND setting, the OS user, and the state
and rules directories.

No logic changes. make check passes.

Model: deepseek-v4-pro

internal/config/config_test.go

@@ -254,12 +254,12 @@ func TestDefaults(t *testing.T) {
 		AttackBanDuration:    7 * 24 * time.Hour,
 		MaxBans:              5000,
 		BanScopeV4Prefix:     32,
-		StateDir:             "/var/lib/smallwebwaf",
+		StateDir:             "/var/lib/sww",
 		StateWriteDelay:      10 * time.Second,
 		StateCounterInterval: 15 * time.Minute,
 		MetricsToken:         "",
 		MetricsTopN:          50,
-		RulesDir:             "/etc/smallwebwaf/rules.d",
+		RulesDir:             "/etc/sww/rules.d",
 		RulesEnabled:         true,
 	})
 	wantLookupSettings(t, cfg, config.Config{
@@ -588,7 +588,7 @@ func TestInvalidCoreRuleSetSettingStopsTheStart(t *testing.T) {
 	const (
 		notParanoiaLevel = " is not a paranoia level, from 1 to 4"
 		setupRule        = " is from 900000 to 900999, the ids of the rules that set " +
-			"the Core Rule Set up and of smallwebwaf's own, which cannot be switched off"
+			"the Core Rule Set up and of sww's own, which cannot be switched off"
 	)
 
 	for _, tc := range []struct{ name, value, want string }{
@@ -627,10 +627,11 @@ func TestInvalidCoreRuleSetSettingStopsTheStart(t *testing.T) {
 			wafBodyLimit, "128KB",
 			`"128KB" is not a size such as 512K, 100M or 5G, or off`,
 		},
-		{wafBodyLimit, "65K", `"65K" is more than 64K, the most servewaf gets of a body`},
+		{wafBodyLimit, "65K", `"65K" is more than 64K, the most discriminator ` +
+			`gets of a body`},
 		{
 			wafBodyLimit, "65537",
-			`"65537" is more than 64K, the most servewaf gets of a body`,
+			`"65537" is more than 64K, the most discriminator gets of a body`,
 		},
 	} {
 		t.Run(tc.name+"="+tc.value, func(t *testing.T) {
@@ -856,7 +857,7 @@ func TestAlertSettingsAsSet(t *testing.T) {
 	const (
 		webhook = "https://alerts.example:8443/hooks/waf?team=ops"
 		slack   = "https://hooks.slack.example/services/T0123/B4567/abcdef"
-		ntfy    = "https://ntfy.example/smallwebwaf-alerts"
+		ntfy    = "https://ntfy.example/sww-alerts"
 		token   = "tk_0123456789abcdefghijklmnopq"
 	)
 
@@ -904,17 +905,17 @@ func TestInvalidAlertSettingStopsTheStart(t *testing.T) {
 	t.Parallel()
 
 	wantStartStopped(t, []struct{ name, value string }{
-		{alertWebhookURL, "alerts.example/smallwebwaf"},
+		{alertWebhookURL, "alerts.example/sww"},
 		{alertWebhookURL, "ftp://alerts.example/"},
-		{alertWebhookURL, "https:///smallwebwaf"},
+		{alertWebhookURL, "https:///sww"},
 		{alertWebhookURL, "https://user:password@alerts.example/"},
 		{alertWebhookURL, "https://alerts.example/#top"},
 		{alertWebhookURL, "https://alerts.example:0/"},
 		{alertWebhookURL, "https://alerts.example:65536/"},
 		{alertSlackWebhookURL, "hooks.slack.example/services/T0123"},
 		{alertSlackWebhookURL, "https://user:password@hooks.slack.example/"},
-		{alertNtfyURL, "ntfy://ntfy.example/smallwebwaf-alerts"},
-		{alertNtfyURL, "https://ntfy.example/smallwebwaf-alerts#top"},
+		{alertNtfyURL, "ntfy://ntfy.example/sww-alerts"},
+		{alertNtfyURL, "https://ntfy.example/sww-alerts#top"},
 		{alertWebhookHeaders, "Authorization"},
 		{alertWebhookHeaders, "X Team:ops"},
 		{alertWebhookHeaders, ":ops"},
@@ -994,7 +995,7 @@ func TestWebhookURLIsLoggedWithoutItsPathOrQueryAndNeverShown(t *testing.T) {
 		_, err := config.FromEnvironment(environment{alertWebhookURL: value}.lookupEnv)
 
 		want := alertWebhookURL + ": is not an http or https URL without a user or " +
-			"a fragment, such as https://alerts.example/smallwebwaf"
+			"a fragment, such as https://alerts.example/sww"
 		if err == nil || err.Error() != want {
 			t.Errorf("error %v, want %s", err, want)
 		}
@@ -1008,7 +1009,7 @@ func TestSlackAndNtfySettingsAreLoggedWithoutTheirSecrets(t *testing.T) {
 
 	cfg := fromEnvironment(t, environment{
 		alertSlackWebhookURL: "https://hooks.slack.example/services/T0123/B4567/abcdef",
-		alertNtfyURL:         "https://ntfy.example/smallwebwaf-alerts",
+		alertNtfyURL:         "https://ntfy.example/sww-alerts",
 		alertNtfyToken:       token,
 	})
 
@@ -1027,7 +1028,7 @@ func TestSlackAndNtfySettingsAreLoggedWithoutTheirSecrets(t *testing.T) {
 		}
 	}
 
-	for _, secret := range []string{"T0123", "smallwebwaf-alerts", token} {
+	for _, secret := range []string{"T0123", "sww-alerts", token} {
 		if strings.Contains(logged, secret) {
 			t.Errorf("%s in the settings logged: %s", secret, logged)
 		}
@@ -1058,7 +1059,7 @@ func TestInstanceNameWithAControlCharacterStopsTheStartOnlyWithNtfySet(t *testin
 	const name = "fsn1app1\r"
 
 	_, err := config.FromEnvironment(environment{
-		instanceName: name, alertNtfyURL: "https://ntfy.example/smallwebwaf-alerts",
+		instanceName: name, alertNtfyURL: "https://ntfy.example/sww-alerts",
 	}.lookupEnv)
 
 	want := instanceName + `: "fsn1app1\r" holds a control character, such as the ` +
@@ -2039,7 +2040,7 @@ func TestInvalidBanOrStateValueStopsTheStart(t *testing.T) {
 		{maxBanDuration, off}, {maxBanDuration, "1w"}, {attackBanDuration, off},
 		{maxBans, off}, {maxBans, "0"}, {maxBans, "5K"},
 		{banScopeV4Prefix, "33"}, {banScopeV4Prefix, "-1"}, {banScopeV4Prefix, "/24"},
-		{stateDir, ""}, {stateDir, "state"}, {stateDir, "./var/lib/smallwebwaf"},
+		{stateDir, ""}, {stateDir, "state"}, {stateDir, "./var/lib/sww"},
 		{stateWriteDelay, off}, {stateWriteDelay, "0s"},
 		{stateCounterInterval, off}, {stateCounterInterval, "15"},
 	})
@@ -2310,7 +2311,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		attackBanDuration:    "7d",
 		maxBans:              "5000",
 		banScopeV4Prefix:     "32",
-		stateDir:             "/var/lib/smallwebwaf",
+		stateDir:             "/var/lib/sww",
 		stateWriteDelay:      "10s",
 		stateCounterInterval: "15m",
 		adminToken:           "",
@@ -2319,7 +2320,7 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		instanceName:         hostname,
 		logRequestHeaders:    defaultLogRequestHeaders,
 		logLevel:             "info",
-		rulesDir:             "/etc/smallwebwaf/rules.d",
+		rulesDir:             "/etc/sww/rules.d",
 		rulesEnabled:         "true",
 		wafMode:              config.WAFModeBlock,
 		wafParanoiaLevel:     "1",