Rename the program to sww and its deciding daemon to discriminator (closes #218)

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 OS user, and the state and rules directories.
The SWWAF_ environment variables take the SWW_ form.

No logic changes. make check passes.

Model: deepseek-v4-pro

internal/remotelog/remotelog.go

@@ -1,5 +1,5 @@
-// Package remotelog sends the lines smallwebwaf writes on stdout to the
-// remote log endpoint, SWWAF_LOG_REMOTE_URL, as the "Request log" section
+// Package remotelog sends the lines sww writes on stdout to the
+// remote log endpoint, SWW_LOG_REMOTE_URL, as the "Request log" section
 // of SPEC.md describes: each line as the message of an RFC 5424 syslog
 // record, over UDP, TCP or TLS. Lines wait in a bounded buffer, so a slow
 // or unreachable endpoint never holds up a request or stdout.
@@ -24,7 +24,7 @@ import (
 	"sneak.berlin/go/smallwebwaf/internal/requestlog"
 )
 
-// The forms of SWWAF_LOG_REMOTE_URL, by its scheme.
+// The forms of SWW_LOG_REMOTE_URL, by its scheme.
 const (
 	SchemeUDP = "syslog+udp"
 	SchemeTCP = "syslog+tcp"
@@ -56,18 +56,18 @@ const (
 
 // Params are what New needs.
 type Params struct {
-	// URL is the endpoint (SWWAF_LOG_REMOTE_URL): SchemeUDP, SchemeTCP or
+	// URL is the endpoint (SWW_LOG_REMOTE_URL): SchemeUDP, SchemeTCP or
 	// SchemeTLS, a host and a port.
 	URL *url.URL
 	// RootCAs are the certificates a SchemeTLS endpoint's certificate
-	// must chain to (SWWAF_LOG_REMOTE_TLS_CA_FILE), nil for the host's.
+	// must chain to (SWW_LOG_REMOTE_TLS_CA_FILE), nil for the host's.
 	RootCAs *x509.CertPool
 	// Buffer is the most lines held while they wait to be sent
-	// (SWWAF_LOG_REMOTE_BUFFER).
+	// (SWW_LOG_REMOTE_BUFFER).
 	Buffer int
 	// Facility is the number of the records' syslog facility
-	// (SWWAF_LOG_REMOTE_FACILITY), and AppName their APP-NAME
-	// (SWWAF_LOG_REMOTE_APP_NAME).
+	// (SWW_LOG_REMOTE_FACILITY), and AppName their APP-NAME
+	// (SWW_LOG_REMOTE_APP_NAME).
 	Facility int
 	AppName  string
 }
@@ -243,7 +243,7 @@ func (s *Sender) send(ctx context.Context, processLog *slog.Logger) net.Conn {
 			}
 		}
 
-		processLog.Warn("sending to SWWAF_LOG_REMOTE_URL failed",
+		processLog.Warn("sending to SWW_LOG_REMOTE_URL failed",
 			"error", err.Error(), "connecting_again_in", delay.String())
 
 		select {