The seat file follows the join, not the ghost

Joining a new room while an old seat file lingered kept the OLD room
id beside the NEW room's token — orphaning the fresh seat as an
unkickable lobby ghost the moment the file was cleared. A join now
records the room it actually joined; only resumes inherit the file.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF

tools/claude-seat.mjs

@@ -101,7 +101,8 @@ ws.on("message", (raw) => {
   const msg = JSON.parse(raw.toString());
   if (msg.type === "error") die(`SERVER: ${msg.message}`);
   if (msg.type === "seat") {
-    const s = { roomId: seat?.roomId ?? args[0]?.toUpperCase(), name: msg.playerId, token: msg.token };
+    // A join names its room explicitly; only a resume inherits the file's.
+    const s = { roomId: verb === "join" ? args[0].toUpperCase() : seat.roomId, name: msg.playerId, token: msg.token };
     writeFileSync(SEAT_FILE, JSON.stringify(s));
     if (verb === "join") { console.log(`seated as ${msg.playerId} in ${s.roomId}`); afterJoin(); }
   }