Rename the settings whose names do not say what they control (closes #234)

Applies the setting renames of the naming audit under the SWW_WAF_ and
SWW_RPROXY_ prefixes, with sneak's names for the IP reputation cache
time and the two time limits, which now take milliseconds. The rproxy
log field default_disposition becomes waf_backend_no_answer, and
config.Config and config.FromEnvironment become config.WAF and
config.WAFFromEnvironment. Go fields, test names and prose follow. No
aliases; nothing reads the old names.

Model: opus-5-5

internal/waf/alerts_test.go

@@ -57,7 +57,7 @@ func TestAttackBanRaisesABanAlertThenAPermanentBanAlert(t *testing.T) {
 	t.Parallel()
 
 	s, clk, server, queue := startWithAlerts(t, map[string]string{
-		rulesDir: writeRules(t, testRules),
+		ruleFilesDir: writeRules(t, testRules),
 	})
 	start := clk.Now()
 	netblock := netip.MustParsePrefix(client + "/32")
@@ -121,7 +121,7 @@ func TestObserveModeRaisesTheBanAlertsItWouldHave(t *testing.T) {
 	s, clk, server, queue := startWithAlerts(t, map[string]string{
 		mode:               observe,
 		rateLimitPerMinute: "2",
-		rulesDir:           writeRules(t, testRules),
+		ruleFilesDir:       writeRules(t, testRules),
 	})
 	start := clk.Now()
 
@@ -209,7 +209,7 @@ func TestObserveModeWorksOutABanOnlyWhenItsAlertWouldBeSent(t *testing.T) {
 	s, _, _, queue := startWithAlerts(t, map[string]string{
 		mode:               observe,
 		rateLimitPerMinute: "2",
-		rulesDir:           writeRules(t, testRules),
+		ruleFilesDir:       writeRules(t, testRules),
 		alertMaxPerHour:    "2",
 	})