Support 2-6 players: the L, the cross, and the 3x2 from the rulebook

Three player counts join the square and the column: 3 players get the
stair/L with the AUTO WARP joining the two openings that face the
concave notch (convex openings pair geometrically — flagged as
interpretation of the diagram's letters); 5 players get the plus/cross
with tip-to-tip wraps and aisle-warp corners; 6 players get the 3x2
rectangle with straight-across wraps. All six verified layouts are
drawn on, so no count repeats a sector. Rooms accept up to six seats;
the lobby copy follows. 122 tests passing.

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

packages/web/src/App.svelte

@@ -549,7 +549,7 @@
     <section class="boxlid">
       <div class="boxlid-inner">
         <div class="boxlid-title small">Room {net.roomId}</div>
-        <div class="boxlid-tag">Share the code. Two or four wizards enter the maze.</div>
+        <div class="boxlid-tag">Share the code. Two to six wizards enter the maze.</div>
         <ul class="roster">
           {#each net.players as p (p)}
             <li><span class="dot" style:background={playerColor(p)}></span>{p}{p === net.hostId ? " — host" : ""}</li>
@@ -562,10 +562,10 @@
           </label>
           <button
             class="stamp big"
-            disabled={net.players.length !== 2 && net.players.length !== 4}
+            disabled={net.players.length < 2 || net.players.length > 6}
             onclick={() => net.start(withExpansion)}
           >
-            Flip the boards ({net.players.length} of 2 or 4)
+            Flip the boards ({net.players.length} wizard{net.players.length === 1 ? "" : "s"})
           </button>
         {:else}
           <p class="waiting">Waiting for {net.hostId} to flip the boards…</p>