fix: scene clear race, path editor anchors, avatar cover, team color crash

Clear scene now patches traps/tokens/npcTokens atomically and updateScene merges against a fresh scene snapshot. Align NPC path-editor previews on token center, default new paths to fixed facing, size avatars by natural aspect for cover, and read team color synchronously from the picker.

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

app/shared/types/tokenPath.test.ts

@@ -2,8 +2,10 @@ import assert from 'node:assert/strict';
 import test from 'node:test';
 
 import {
+  createEmptyTokenPath,
   findNearestAheadDistance,
   normalizeTokenPath,
+  normalizeTokenPathFacingMode,
   reverseTokenPathPoints,
   rotateTokenPathByCwSteps,
   sampleTokenPathAtProgress,
@@ -12,6 +14,29 @@ import {
   TOKEN_PATH_MIN_POINT_DIST,
 } from './tokenPath';
 
+void test('createEmptyTokenPath defaults to fixed facing (no auto-rotate)', () => {
+  const empty = createEmptyTokenPath();
+  assert.equal(empty.facingMode, 'fixed');
+  assert.equal(empty.fixedRotationDeg, 0);
+});
+
+void test('normalizeTokenPathFacingMode: missing → fixed; explicit tangent kept', () => {
+  assert.equal(normalizeTokenPathFacingMode(undefined), 'fixed');
+  assert.equal(normalizeTokenPathFacingMode('fixed'), 'fixed');
+  assert.equal(normalizeTokenPathFacingMode('tangentSmooth'), 'tangentSmooth');
+});
+
+void test('normalizeTokenPath defaults facingMode to fixed when omitted', () => {
+  const p = normalizeTokenPath({
+    points: [
+      { nx: 0.1, ny: 0.1 },
+      { nx: 0.5, ny: 0.1 },
+    ],
+  });
+  assert.ok(p);
+  assert.equal(p!.facingMode, 'fixed');
+});
+
 void test('tryAppendPathPoint rejects double-click distance', () => {
   const a = tryAppendPathPoint([], { nx: 0.1, ny: 0.1 });
   assert.ok(a);

app/shared/types/tokenPath.ts

@@ -56,13 +56,13 @@ export function createEmptyTokenPath(): TokenPath {
     durationSec: DEFAULT_TOKEN_PATH_DURATION_SEC,
     startMode: 'onEnter',
     delaySec: DEFAULT_TOKEN_PATH_DELAY_SEC,
-    facingMode: 'tangentSmooth',
+    facingMode: 'fixed',
     fixedRotationDeg: 0,
   };
 }
 
 export function normalizeTokenPathFacingMode(raw: unknown): TokenPathFacingMode {
-  return raw === 'fixed' ? 'fixed' : 'tangentSmooth';
+  return raw === 'tangentSmooth' ? 'tangentSmooth' : 'fixed';
 }
 
 export function normalizeTokenPathLoopMode(raw: unknown, closed: boolean): TokenPathLoopMode {