[upstream #16819] Invalidate the theme cache when resolver output changes without a role change #290

The deployment-theme cache version is themeRoleFingerprint(), derived from role names and THEME_VERSION. A release that changes a bundled palette value, a fallback derivation or a resolver output without changing the role set leaves the old entry valid, so the boot script replays stale styling once.

Fix direction: fold an independent resolver epoch (or a hash of the resolved default output) into the cache version so such releases invalidate entries without touching THEME_VERSION.