Boobytrap tokens land where you can see them

The four placements accumulated invisibly until the last click cast
the spell. Each token now marks its square as it is placed, numbered
in click order — the 1 is the real trap — and tapping a placed token
lifts it again, since the four must be distinct squares.

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

packages/web/src/App.svelte

@@ -470,7 +470,11 @@
       return;
     }
     if (selectedCard?.cardId === "boobytrap") {
-      trapCells = [...trapCells, cell];
+      // Tapping a placed token lifts it again; the four must be distinct.
+      const already = trapCells.findIndex((c) => cellKey(c) === cellKey(cell));
+      trapCells = already !== -1
+        ? trapCells.filter((_, i) => i !== already)
+        : [...trapCells, cell];
       if (trapCells.length === 4) {
         dispatch({ type: "cast", instanceId: selectedCard.instanceId, params: { cells: trapCells } });
         clearSelection();
@@ -1224,6 +1228,7 @@
           onCreatureClick={clickCreature}
           onWarpClick={clickWarp}
           markedCell={tradeFrom ?? pendingTeleport}
+          markedCells={trapCells.length > 0 ? trapCells : null}
           markedSector={pendingSectorOrigin}
           ghostSlots={relocateGhosts}
           onGhostClick={clickGhostSlot}