feat(scene): keep map tokens with preview rotation

When previewRotationDeg changes, remap non-player, NPC and trap
markers (plus live session token overrides) so they stay on the art.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/main/players/sceneNpcTokensSessionStore.ts

@@ -6,6 +6,7 @@ import {
   type SceneNpcTokensSessionState,
 } from '../../shared/types/appPlayers';
 import { normalizeNpcDisposition } from '../../shared/types/npcDisposition';
+import { rotateMapNormPointByCwSteps } from '../../shared/types/scenePreviewRotation';
 
 function emptyState(revision = 1): SceneNpcTokensSessionState {
   return {
@@ -63,6 +64,34 @@ export class SceneNpcTokensSessionStore {
     return this.state;
   }
 
+  /** Rotate session position overrides with the scene preview (CSS rotate steps). */
+  rotateMapCwSteps(steps: number): SceneNpcTokensSessionState {
+    const n = ((steps % 4) + 4) % 4;
+    if (n === 0) return this.state;
+    const ids = Object.keys(this.state.byPlacementId);
+    if (ids.length === 0) return this.state;
+    let changed = false;
+    const byPlacementId: SceneNpcTokensSessionState['byPlacementId'] = {};
+    for (const id of ids) {
+      const prev = this.state.byPlacementId[id];
+      if (!prev) continue;
+      if (typeof prev.nx === 'number' && typeof prev.ny === 'number') {
+        const p = rotateMapNormPointByCwSteps(prev.nx, prev.ny, n);
+        byPlacementId[id] = { ...prev, nx: p.nx, ny: p.ny };
+        changed = true;
+      } else {
+        byPlacementId[id] = prev;
+      }
+    }
+    if (!changed) return this.state;
+    this.state = {
+      revision: this.state.revision + 1,
+      byPlacementId,
+      scale: this.state.scale,
+    };
+    return this.state;
+  }
+
   dispatch(event: SceneNpcTokensSessionEvent): SceneNpcTokensSessionState {
     switch (event.kind) {
       case 'clear':