feat(offline): per-seat medals in local games; drop the you-won text + lobby medal

For a local (offline) game the outcome is not always about a single
'you' (hotseat is 2-4 players), so:
- Game.svelte: a finished local game no longer shows the viewer-centric
  'you won/lost/draw' status; instead each seat plaque shows a per-seat
  place medal, left of the name (result.seatMedal — trophy for the winner,
  then places by score; a draw medals everyone).
- Lobby.svelte: a local game shows no lobby medal (resultBadge is
  viewer-centric and no seat matches the account) — its result lives on
  the in-game plaques.
- result.ts: seatMedal(game, seat), unit-tested.

ui/src/game/Game.svelte

@@ -20,6 +20,7 @@
   import type { EvalResult, MoveRecord, MoveResult, StateView, Tile } from '../lib/model';
   import { lastMoveCells, replay } from '../lib/board';
   import { badgeKind } from '../lib/unread';
+  import { seatMedal } from '../lib/result';
   import { historyGrid } from '../lib/history';
   import { centre, premiumGrid } from '../lib/premiums';
   import { variantNameKey, usesStarBlank, BLANK_STAR } from '../lib/variants';
@@ -1496,7 +1497,7 @@
       {#if badge}<span class="unread-dot sbadge-dot" class:nudge={badge === 'nudge'}></span>{/if}
       {#each view.game.seats as s (s.seat)}
         <div class="seat" class:turn={view.game.toMove === s.seat && !gameOver} class:win={s.isWinner}>
-          <div class="nm" class:struck={seatBlocked(s)}>{seatName(s)}</div>
+          <div class="nm" class:struck={seatBlocked(s)}>{#if gameOver && isLocalGameId(id)}<span class="medal" aria-hidden="true">{seatMedal(view.game, s.seat)}</span>{/if}{seatName(s)}</div>
           <div class="sc" class:blockprompt={blockConfirm[s.seat]}>
             {#if blockConfirm[s.seat]}{t('game.blockShort')}{:else if addConfirm[s.seat]}{t('game.addFriendShort')}{:else}{s.score}{/if}
           </div>
@@ -1622,7 +1623,9 @@
     <div class="status">
       <span>{view.bagLen === 0 ? t('game.bagEmpty') : t('game.bag', { n: view.bagLen })}</span>
       {#if gameOver}
-        <strong class="over">{resultText()}</strong>
+        <!-- A local (offline) game shows its result as per-seat medals on the plaques (below), not a
+             viewer-centric "you won/lost" — the outcome is not always about a single "you". -->
+        {#if !isLocalGameId(id)}<strong class="over">{resultText()}</strong>{/if}
       {:else if placement.pending.length === 0}
         <span class="turn-ind">{view.game.hotseat ? t('hotseat.turnOf', { name: hotseatName(view.game.toMove) }) : isMyTurn ? t('game.yourTurn') : turnLabel()}</span>
       {/if}
@@ -1865,6 +1868,10 @@
     overflow: hidden;
     text-overflow: ellipsis;
   }
+  /* The finished-game place medal on a local (offline) seat plaque, left of the name. */
+  .medal {
+    margin-right: 3px;
+  }
   .sc {
     font-weight: 700;
     font-variant-numeric: tabular-nums;