The seat wallet's cap of fifty drops the oldest seats, not the newest

Seats are kept newest first, but the cap kept the tail, so a browser
holding more than fifty threw away the seat it had just taken. Sitting
in that room hid it (each room message remembers the seat again); the
first games poll after moving to another table lost it for good.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/web/src/net.svelte.ts

@@ -754,7 +754,8 @@ class Net {
         for (const key of voided) { if (this.voidedOnce.has(key)) doubted.add(key); }
         this.voidedOnce = voided;
         let kept = this.seats.filter((s) => !doubted.has(`${s.roomId}:${s.name}`));
-        if (kept.length > 50) kept = kept.slice(kept.length - 50);
+        // Newest first (rememberSeat puts a seat at the front): the oldest go.
+        if (kept.length > 50) kept = kept.slice(0, 50);
         if (kept.length !== this.seats.length) {
           this.seats = kept;
           saveSeats(this.seats);