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.