Rename the program to sww and its deciding daemon to discriminator

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/lookup/file.go

@@ -24,7 +24,7 @@ const quietTime = 2 * time.Second
 // FileParams are what OpenFile needs.
 type FileParams struct {
 	// Path is the lookup database, the IPinfo Lite file in its .mmdb form
-	// (SWWAF_LOOKUP_DB_PATH).
+	// (SWW_LOOKUP_DB_PATH).
 	Path string
 	// Now tells the time, normally time.Now.
 	Now func() time.Time
@@ -51,7 +51,7 @@ type File struct {
 }
 
 // record is what the lookup database holds about a network, of the fields
-// smallwebwaf reads.
+// sww reads.
 type record struct {
 	ASN         string `maxminddb:"asn"`
 	ASName      string `maxminddb:"as_name"`
@@ -221,12 +221,12 @@ func (f *File) use(reader *maxminddb.Reader) {
 func read(path string) (*maxminddb.Reader, error) {
 	data, err := os.ReadFile(path) //nolint:gosec // the file the admin names
 	if err != nil {
-		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH cannot be read: %w", err)
+		return nil, fmt.Errorf("SWW_LOOKUP_DB_PATH cannot be read: %w", err)
 	}
 
 	reader, err := maxminddb.OpenBytes(data)
 	if err != nil {
-		return nil, fmt.Errorf("SWWAF_LOOKUP_DB_PATH %s is not a .mmdb file: %w", path, err)
+		return nil, fmt.Errorf("SWW_LOOKUP_DB_PATH %s is not a .mmdb file: %w", path, err)
 	}
 
 	return reader, nil

internal/lookup/file_internal_test.go

@@ -99,9 +99,9 @@ func TestFileThatCannotBeReadIsAnError(t *testing.T) {
 	writeFile(t, notDatabase, "not a lookup database\n")
 
 	for path, want := range map[string]string{
-		missing: "SWWAF_LOOKUP_DB_PATH cannot be read: open " + missing +
+		missing: "SWW_LOOKUP_DB_PATH cannot be read: open " + missing +
 			": no such file or directory",
-		notDatabase: "SWWAF_LOOKUP_DB_PATH " + notDatabase +
+		notDatabase: "SWW_LOOKUP_DB_PATH " + notDatabase +
 			" is not a .mmdb file: error opening database: invalid MaxMind DB file",
 	} {
 		_, err := OpenFile(FileParams{
@@ -216,7 +216,7 @@ func TestReplacementThatCannotBeReadLeavesTheFileInUseWithOneAlert(t *testing.T)
 			Reason: "the lookup database cannot be read, and the one read before stays in use",
 			Detail: map[string]any{
 				"file": path,
-				"error": "SWWAF_LOOKUP_DB_PATH " + path + " is not a .mmdb file: " +
+				"error": "SWW_LOOKUP_DB_PATH " + path + " is not a .mmdb file: " +
 					"error opening database: invalid MaxMind DB file",
 			},
 		})

internal/lookup/lookup.go

@@ -1,6 +1,6 @@
 // Package lookup looks up each client's AS number and country, through
 // the GeoJS web service or in the lookup database, the IPinfo Lite file
-// SWWAF_LOOKUP_DB_PATH names. GeoJS's answers are kept in memory, for at
+// SWW_LOOKUP_DB_PATH names. GeoJS's answers are kept in memory, for at
 // most 100,000 clients and for 7 days each, and are written to
 // lookups.json and read from it by the state package.
 package lookup
@@ -66,7 +66,7 @@ type Params struct {
 	URL string
 	// Timeout is how long a request waits for its client's first answer,
 	// and how long a request to GeoJS may take before it is abandoned
-	// (SWWAF_LOOKUP_TIMEOUT).
+	// (SWW_LOOKUP_TIMEOUT).
 	Timeout time.Duration
 	// Wait is true when a setting needs each request's answer before the
 	// request goes on. Otherwise no request waits for one.

internal/lookup/lookuptest/lookuptest.go

@@ -17,7 +17,7 @@ import (
 const fileMode = 0o600
 
 // Network is what a lookup database holds about a netblock, of the fields
-// smallwebwaf reads: its AS number, such as AS64496, the AS's name, and
+// sww reads: its AS number, such as AS64496, the AS's name, and
 // its country, such as DE.
 type Network struct {
 	ASN     string