feat: add host flag to configure web UI listen address

Co-authored-by: Copilot <copilot@github.com>

cmd/client/main.go

@@ -15,6 +15,7 @@ import (
 func main() {
 	dataDir := flag.String("data-dir", "./thefeeddata", "Data directory for config, cache, and sessions")
 	port := flag.Int("port", 8080, "Web UI port")
+	host := flag.String("host", "127.0.0.1", "Web UI listen address (host), use 0.0.0.0 to expose to LAN")
 	password := flag.String("password", "", "Admin password for web UI (empty = no auth)")
 	showVersion := flag.Bool("version", false, "Show version and exit")
 	flag.Usage = func() {
@@ -28,13 +29,19 @@ func main() {
 		os.Exit(0)
 	}
 
-	srv, err := web.New(*dataDir, *port, *password)
+	srv, err := web.New(*dataDir, *port, *host, *password)
 	if err != nil {
 		log.Fatalf("Failed to start: %v", err)
 	}
 
 	// Try to open browser automatically
-	url := fmt.Sprintf("http://127.0.0.1:%d", *port)
+
+	// Open browser on the chosen host (localhost if default)
+	browserHost := *host
+	if browserHost == "0.0.0.0" {
+		browserHost = "127.0.0.1"
+	}
+	url := fmt.Sprintf("http://%s:%d", browserHost, *port)
 	go openBrowser(url)
 
 	if err := srv.Run(); err != nil {

internal/web/web.go

@@ -87,6 +87,7 @@ type lastScanData struct {
 type Server struct {
 	dataDir  string
 	port     int
+	host     string
 	password string // admin password; empty means no auth
 
 	mu               sync.RWMutex
@@ -139,7 +140,7 @@ type Server struct {
 }
 
 // New creates a new web server.
-func New(dataDir string, port int, password string) (*Server, error) {
+func New(dataDir string, port int, host string, password string) (*Server, error) {
 	if err := os.MkdirAll(dataDir, 0700); err != nil {
 		return nil, fmt.Errorf("create data dir: %w", err)
 	}
@@ -156,6 +157,7 @@ func New(dataDir string, port int, password string) (*Server, error) {
 	s := &Server{
 		dataDir:        dataDir,
 		port:           port,
+		host:           host,
 		password:       password,
 		messages:       make(map[int][]protocol.Message),
 		clients:        make(map[chan string]struct{}),
@@ -230,9 +232,10 @@ func (s *Server) Run() error {
 	mux.HandleFunc("/api/scanner/presets", s.handleScannerPresets)
 	mux.HandleFunc("/", s.handleIndex)
 
-	addr := fmt.Sprintf("127.0.0.1:%d", s.port)
+	// Listen on the specified host (default 127.0.0.1)
+	addr := fmt.Sprintf("%s:%d", s.host, s.port)
 	log.Printf("thefeed client %s", version.Version)
-	fmt.Printf("\n  Open in browser: http://%s\n\n", addr)
+	fmt.Printf("\n  Open in browser: http://%s:%d\n\n", s.host, s.port)
 
 	if s.fetcher != nil {
 		if ls := s.loadLastScan(); ls != nil {