Read every setting through viper and rename the settings (closes #211)

Every setting of discriminator and rproxy is read through viper, in place
of the os.LookupEnv function Main passed down. NewViper turns AutomaticEnv
and AllowEmptyEnv on, so a setting that is set but empty reads as set. A
setting may also be given as a file, the _FILE form, which rproxy's
settings now have too; rproxy still writes nothing to disk.

The settings are renamed. Discriminator's take the prefix SWW_WAF_,
rproxy's take SWW_RPROXY_, and the shared SWW_COMMAND keeps SWW_. The Core
Rule Set's settings take SWW_WAF_CORE_RULE_SET_ rather than SWW_WAF_WAF_.
Every place a name appeared changed: the code, the viper keys, tests,
documents, examples, the README's settings table and the image files.

Model: deepseek-v4-pro

internal/anomaly/anomaly.go

@@ -28,16 +28,16 @@ const maxCounters = 20000
 // alerts name them.
 const (
 	// ScopeClient is one client: an IPv4 address, or an IPv6 netblock of
-	// SWW_IPV6_GROUP_PREFIX.
+	// SWW_WAF_IPV6_GROUP_PREFIX.
 	ScopeClient = "client"
-	// ScopeNet is the netblock around a client, SWW_ANOMALY_NET_V4_PREFIX
-	// or SWW_ANOMALY_NET_V6_PREFIX long.
+	// ScopeNet is the netblock around a client, SWW_WAF_ANOMALY_NET_V4_PREFIX
+	// or SWW_WAF_ANOMALY_NET_V6_PREFIX long.
 	ScopeNet = "net"
 	// ScopeASN is an AS number.
 	ScopeASN = "asn"
 	// ScopeTotal is the whole service.
 	ScopeTotal = "total"
-	// ScopeWatch is a named netblock of SWW_WATCH_NETS.
+	// ScopeWatch is a named netblock of SWW_WAF_WATCH_NETS.
 	ScopeWatch = "watch"
 )
 
@@ -62,7 +62,7 @@ type Thresholds struct {
 	BytesPerHour      int64
 }
 
-// NamedNetblock is a netblock SWW_WATCH_NETS names.
+// NamedNetblock is a netblock SWW_WAF_WATCH_NETS names.
 type NamedNetblock struct {
 	Name     string
 	Netblock netip.Prefix
@@ -70,14 +70,14 @@ type NamedNetblock struct {
 
 // Params are what New needs.
 type Params struct {
-	// The thresholds of each scope: SWW_ANOMALY_CLIENT_*,
-	// SWW_ANOMALY_NET_*, SWW_ANOMALY_ASN_*, SWW_ANOMALY_TOTAL_* and
-	// SWW_WATCH_*.
+	// The thresholds of each scope: SWW_WAF_ANOMALY_CLIENT_*,
+	// SWW_WAF_ANOMALY_NET_*, SWW_WAF_ANOMALY_ASN_*, SWW_WAF_ANOMALY_TOTAL_* and
+	// SWW_WAF_WATCH_*.
 	Client, Net, ASN, Total, Watch Thresholds
 	// NetV4Prefix and NetV6Prefix are the lengths of the netblock around a
-	// client (SWW_ANOMALY_NET_V4_PREFIX and SWW_ANOMALY_NET_V6_PREFIX).
+	// client (SWW_WAF_ANOMALY_NET_V4_PREFIX and SWW_WAF_ANOMALY_NET_V6_PREFIX).
 	NetV4Prefix, NetV6Prefix int
-	// NamedNetblocks are SWW_WATCH_NETS.
+	// NamedNetblocks are SWW_WAF_WATCH_NETS.
 	NamedNetblocks []NamedNetblock
 	// Alerts receive the anomaly alerts.
 	Alerts *alerts.Queue
@@ -107,13 +107,13 @@ type Request struct {
 	Host string
 	// Client is the client's address, and ClientGroup the client it is
 	// counted as: its IPv4 address, or the IPv6 netblock of
-	// SWW_IPV6_GROUP_PREFIX its address is in.
+	// SWW_WAF_IPV6_GROUP_PREFIX its address is in.
 	Client      netip.Addr
 	ClientGroup netip.Prefix
 	// ASN, ASName and Country are the client's as looked up, each "" when
 	// unknown.
 	ASN, ASName, Country string
-	// Bytes are the request's bytes, as SWW_BYTES_COUNT counts them.
+	// Bytes are the request's bytes, as SWW_WAF_BYTES_COUNT counts them.
 	Bytes int64
 }