Mark overrides in gold instead of bold, and up the hierarchy

An inspector label whose value deviates from its base was drawn bold, which is
easy to miss next to the regular labels and says nothing in the hierarchy, where
a folded subtree could hide a change entirely.

The colour now lives as a theme token (`override`, #f2c84b) used by both the
inspector labels and the hierarchy rows. Whether a row deviates is decided by
`src/core/properties/deviation.ts`: `objectDeviates` compares an object against
what it follows -- the container template for content, the asset otherwise --
and `deviationMarks` carries the mark up to every ancestor, so a folded subtree
still shows that something inside was changed.

`deviationMarks` takes the stored holder, not the resolved one: in the resolved
view container content looks like an ordinary object and `instanceTargetOf`
would compare against the asset, marking every instance.

Covered by 3 unit tests and 5 e2e checks, including one that strips an object's
own overrides to prove the row stays gold for a deviating child and restores
them byte for byte. Full suite remote on the RTX 4070: 275 checks, all passed.

src/editor/debugHook.ts

@@ -1,4 +1,4 @@
-import { type Application, type Container, Rectangle, Text } from 'pixi.js';
+import { type Application, Color, type ColorSource, type Container, Rectangle, Text } from 'pixi.js';
 import { resolveObjects } from '../core/model/instance';
 import { findObjectHolder } from '../core/model/Project';
 import { Button, ui, Widget } from '../ui';
@@ -34,6 +34,20 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
     const p = node.getGlobalPosition();
     return { x: p.x + node.width / 2, y: p.y + node.height / 2 };
   };
+  /** Fill colour of a visible text, as `#rrggbb` – what tells an override label from a plain one. */
+  const textColor = (text: string): string | null => {
+    let found: string | null = null;
+    const walk = (node: Container): void => {
+      if (found !== null || !node.visible) return;
+      if (node instanceof Text && node.text === text) {
+        found = new Color(node.style.fill as ColorSource).toHex();
+        return;
+      }
+      for (const child of node.children) walk(child);
+    };
+    walk(app.stage);
+    return found;
+  };
   /**
    * The visible text of the overlay layer, in drawing order – everything an open popup shows.
    * Menus hide filtered-out entries, so this is also what a search box currently leaves.
@@ -118,6 +132,7 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
     objectsOf,
     sceneObjects: () => (state.activeScene ? objectsOf(state.activeScene.id) : []),
     locate,
+    textColor,
     overlayTexts,
     overlayRect,
     textOverflows,
@@ -159,6 +174,7 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
     /** Rows the hierarchy shows – collapsed subtrees are not in here. */
     hierarchyOrder: () => hierarchy.rowOrder(),
     hierarchyChevron: (id: string) => hierarchy.chevronPosition(id),
+    hierarchyRowColor: (id: string) => hierarchy.rowColor(id),
     hierarchyExpandAll: () => hierarchy.expandAll(),
     hierarchyCollapseAll: () => hierarchy.collapseAll(),
     /** The colour actually on screen at a point, as `#rrggbb` – what was drawn, not what the model says. */