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/state/state.go

@@ -123,11 +123,11 @@ type Params struct {
 	// CacheDir that of the cache files (SWW_WAF_CACHE_DIR).
 	Dir      string
 	CacheDir string
-	// WriteDelay is how long after a ban is made bans.json is written
-	// (SWW_WAF_STATE_WRITE_DELAY), and CounterInterval how often every file
-	// is (SWW_WAF_STATE_COUNTER_INTERVAL).
-	WriteDelay      time.Duration
-	CounterInterval time.Duration
+	// BansWriteDelay is how long after a ban is made bans.json is written
+	// (SWW_WAF_BANS_WRITE_DELAY), and WriteInterval how often every file
+	// is (SWW_WAF_STATE_WRITE_INTERVAL).
+	BansWriteDelay time.Duration
+	WriteInterval  time.Duration
 	// Ledger, Limiter, GeoJS, Lists, DNSBL, AbuseIPDB, RouteWatch, Alerts and
 	// Anomalies hold the state. RouteWatch is nil while SWW_WAF_ROUTEWATCH_URL is
 	// unset, and routewatch.json then holds no answers. Alerts also receive a
@@ -318,13 +318,13 @@ func Load(params Params) (*Files, error) {
 	return f, nil
 }
 
-// Run writes bans.json WriteDelay after a ban is made, with every ban
-// made in between, and every file every CounterInterval, until ctx is
+// Run writes bans.json BansWriteDelay after a ban is made, with every ban
+// made in between, and every file every WriteInterval, until ctx is
 // done. A write that fails is logged, raised as a file_error alert, and
 // the file is written again at its next write. Each write takes in an
 // admin's edit of its file first, as writeFile describes.
 func (f *Files) Run(ctx context.Context) {
-	interval := time.NewTicker(f.params.CounterInterval)
+	interval := time.NewTicker(f.params.WriteInterval)
 	defer interval.Stop()
 
 	var bansDue <-chan time.Time // nil while no ban waits to be written
@@ -335,7 +335,7 @@ func (f *Files) Run(ctx context.Context) {
 			return
 		case <-f.params.Ledger.Changed():
 			if bansDue == nil {
-				bansDue = time.After(f.params.WriteDelay)
+				bansDue = time.After(f.params.BansWriteDelay)
 			}
 		case <-bansDue:
 			bansDue = nil