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/sww/waf_test.go

@@ -96,7 +96,7 @@ func TestMainRunsWAF(t *testing.T) {
 		listenAddr+"="+localhost+":0",
 		stateDir+"="+dir,
 		cacheDir+"="+dir,
-		rulesDir+"="+t.TempDir(),
+		ruleFilesDir+"="+t.TempDir(),
 		lookupSource+"=off")
 
 	exited := startProcess(t, cmd)
@@ -278,9 +278,9 @@ func TestWAFKeepsItsBansAcrossARestartAndNeedsNoApp(t *testing.T) {
 	t.Parallel()
 
 	env := map[string]string{
-		listenAddr: localhost + ":0",
-		stateDir:   t.TempDir(),
-		rulesDir:   filepath.Join("..", "..", "share", "rules.d"),
+		listenAddr:   localhost + ":0",
+		stateDir:     t.TempDir(),
+		ruleFilesDir: filepath.Join("..", "..", "share", "rules.d"),
 	}
 
 	runWAF(t, env, func(addr string) {