feat(tokens): app-local non-player tokens with session moves and UI polish

Add token library/placements, keep play-time moves for the session, lock presentation interactions, and fix export/import modal layout plus freeform trap label.

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

app/main/tokens/sceneTokensSessionStore.ts

@@ -0,0 +1,54 @@
+import type { SceneTokensSessionEvent, SceneTokensSessionState } from '../../shared/types';
+
+function emptyState(): SceneTokensSessionState {
+  return {
+    revision: 1,
+    byPlacementId: {},
+  };
+}
+
+export class SceneTokensSessionStore {
+  private state: SceneTokensSessionState = emptyState();
+
+  getState(): SceneTokensSessionState {
+    return this.state;
+  }
+
+  reset(): SceneTokensSessionState {
+    if (Object.keys(this.state.byPlacementId).length === 0) return this.state;
+    this.state = {
+      revision: this.state.revision + 1,
+      byPlacementId: {},
+    };
+    return this.state;
+  }
+
+  dispatch(event: SceneTokensSessionEvent): SceneTokensSessionState {
+    switch (event.kind) {
+      case 'clear':
+        return this.reset();
+      case 'move': {
+        const placementId = String(event.placementId ?? '');
+        if (!placementId) return this.state;
+        const nx = Math.max(0, Math.min(1, event.nx));
+        const ny = Math.max(0, Math.min(1, event.ny));
+        if (!Number.isFinite(nx) || !Number.isFinite(ny)) return this.state;
+        const prev = this.state.byPlacementId[placementId];
+        if (prev && prev.nx === nx && prev.ny === ny) return this.state;
+        this.state = {
+          revision: this.state.revision + 1,
+          byPlacementId: {
+            ...this.state.byPlacementId,
+            [placementId]: { nx, ny },
+          },
+        };
+        return this.state;
+      }
+      default: {
+        const _exhaustive: never = event;
+        void _exhaustive;
+        return this.state;
+      }
+    }
+  }
+}