tools: webviewer --host option (default stays 127.0.0.1)

Owner-approved: serve on the Tailscale address only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Tools/webviewer/server.py

@@ -72,13 +72,15 @@ def main():
     parser.add_argument("--mesh-dir", type=Path, default=APP_DIR / "meshes",
                         help="folder containing converted .glb files")
     parser.add_argument("--port", type=int, default=8000)
+    parser.add_argument("--host", default="127.0.0.1",
+                        help="address to bind; default loopback only (e.g. a Tailscale address)")
     args = parser.parse_args()
     if not 0 < args.port < 65536:
         parser.error("--port must be between 1 and 65535")
     args.mesh_dir.mkdir(parents=True, exist_ok=True)
-    server = ThreadingHTTPServer(("127.0.0.1", args.port), make_handler(args.mesh_dir))
+    server = ThreadingHTTPServer((args.host, args.port), make_handler(args.mesh_dir))
     server.daemon_threads = True
-    print(f"VoxelForge viewer: http://127.0.0.1:{args.port}/")
+    print(f"VoxelForge viewer: http://{args.host}:{args.port}/")
     print(f"Mesh folder: {args.mesh_dir.resolve()}")
     try:
         server.serve_forever()