Idiot enforces its card (rev 23) + attack sight-line tracing

Rules rev 23 — IDIOT, per the card and FAQ:
- No handling items: pick up / drop of treasures and objects refused
  (dropping was the exploit: capturing a stolen treasure on your own home,
  or dropping your own treasure underfoot for an instant cure)
- No punching, no thrown dagger / large rock (attacks on players)
- No effect on a victim already carrying one of their own treasures
Ungated (permissive): counteractions are now castable while idiotized (the
one thing the card expressly allows — the gate wrongly blocked them), and
goal-aiding spells (IDIOT_AIDS: destroy-wall, teleport, mad-dash, ...) per
the FAQ's 'you could, however, destroy a wall'.

Sight tracing: while an LOS attack sits on the stack, the board draws the
line it traveled — straight when direct, leg by leg through both warp
mouths (with pulsing rings) when the maze's wraparound carried it. Engine
traceSight/traceSightFor/stackSightTrace; overlay in Board.svelte; shown
live and in replays. Verified against H3PC's cross-board Idiot cast.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0138A8CjeQRpvzKxuMfz1Bqc

packages/web/src/App.svelte

@@ -10,7 +10,7 @@
   import { scheduleFx, type BoardFx } from "./fx";
   import { CREATURE_ART, objectArt, TERRAIN_ART, tokenArt } from "./art";
   import { local } from "./local.svelte";
-  import { allCardDefs, cardDef, isNumberCard, isPermanentDuration, SIDES, stepTarget, cellKey, isMovableObject, sightedCellsFor, type GameView, eligibleCellsFor } from "@wizwar/engine";
+  import { allCardDefs, cardDef, isNumberCard, isPermanentDuration, SIDES, stepTarget, cellKey, isMovableObject, sightedCellsFor, stackSightTrace, type GameView, eligibleCellsFor } from "@wizwar/engine";
   import type { CardInstance, Side } from "@wizwar/engine";
 
   net.connect();
@@ -854,6 +854,10 @@
                                t.position.y === me.position.y && !t.carriedBy),
   );
   /** Squares a selected L.O.S./ADJACENT card can reach; null = no dimming. */
+  // While an LOS attack sits on the stack, draw the line it traveled — the
+  // answer to "how can he even see me?" when sight ran through a warp mouth.
+  const sightTrace = $derived(view ? stackSightTrace(view) : null);
+
   const litCells = $derived.by(() => {
     if (!view || !selectedDef || !yourMoment) return null;
     if (ambushVia || ambushSpell || ambushTrigger) return null; // ambushes aim at the future
@@ -1386,6 +1390,7 @@
           onGhostClick={clickGhostSlot}
           onCellPeek={(c) => peekAt(c)}
           {litCells}
+          {sightTrace}
         />
       </section>