Seat transfer phrases: carry your games to another device

While seated, "transfer seat" in the masthead mints a spoken-word
one-time phrase from the game's own vocabulary (ember-troll-dagger),
good for ten minutes. Typing it into the lobby's "claim a transferred
seat" box on any other device hands over the seat's token, adds the
game to that browser's ledger, and sits you straight down at the
table. Phrases are single-use, expire, are voided by a server restart
(seats never are), and both devices keep the seat afterward — the
phone on the couch and the desktop upstairs can play the same wizard.
Verified end to end: mint, claim, rejoin, and a second claim refused.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/server/src/index.ts

@@ -14,10 +14,12 @@
 import { WebSocketServer, WebSocket } from "ws";
 import type { Command, PlayerId } from "@wizwar/engine";
 import {
+  claimTransferCode,
   createRoom,
   getRoom,
   joinRoom,
   loadPersistedRooms,
+  makeTransferCode,
   redactFor,
   runCommand,
   startGame,
@@ -131,6 +133,20 @@ wss.on("connection", (socket) => {
           broadcast(room, (playerId) => ({ type: "state", view: viewForPlayer(room, playerId) }));
           break;
         }
+        case "makeTransfer": {
+          const room = session.roomId ? getRoom(session.roomId) : undefined;
+          if (!room || !session.playerId) return send(socket, { type: "error", message: "not in a room" });
+          const result = makeTransferCode(room, session.playerId);
+          if ("error" in result) return send(socket, { type: "error", message: result.error });
+          send(socket, { type: "transferCode", code: result.code, expiresAt: result.expiresAt });
+          break;
+        }
+        case "claimTransfer": {
+          const result = claimTransferCode(String(msg.code ?? ""));
+          if ("error" in result) return send(socket, { type: "error", message: result.error });
+          send(socket, { type: "transferClaimed", seat: result });
+          break;
+        }
         case "myGames": {
           // {seats: [{roomId, name, token}]} -> summaries for valid seats.
           const seats = Array.isArray(msg.seats) ? msg.seats : [];