fix: accept bare Pi-hole IPv4 addresses

internal/pihole/client.go

@@ -71,7 +71,11 @@ func New(rawURL string, insecureTLS bool) (*Client, error) {
 }
 
 func normalizeBaseURL(raw string) (string, error) {
-	parsed, err := url.Parse(strings.TrimSpace(raw))
+	raw = strings.TrimSpace(raw)
+	if address := net.ParseIP(raw); address != nil && address.To4() != nil {
+		raw = "http://" + raw
+	}
+	parsed, err := url.Parse(raw)
 	if err != nil || parsed.Host == "" || (parsed.Scheme != "http" && parsed.Scheme != "https") {
 		return "", errors.New("Pi-hole-Adresse muss eine vollständige HTTP- oder HTTPS-URL sein")
 	}

internal/pihole/client_test.go

@@ -101,6 +101,10 @@ func TestNewValidatesAndNormalizesPiHoleURL(t *testing.T) {
 	if err != nil || client.BaseURL() != "http://pihole.local/custom/api" {
 		t.Fatalf("custom path not normalized: %q err=%v", client.BaseURL(), err)
 	}
+	client, err = New("10.0.20.100", false)
+	if err != nil || client.BaseURL() != "http://10.0.20.100/api" {
+		t.Fatalf("bare IPv4 address not normalized: %q err=%v", client.BaseURL(), err)
+	}
 	for _, invalid := range []string{"pi.hole", "ftp://pi.hole", "https://user:pass@pi.hole", "https://pi.hole?sid=secret"} {
 		if _, err := New(invalid, false); err == nil {
 			t.Errorf("invalid URL accepted: %s", invalid)