Resolved by accepting main's restructured brand assets (src/core/assets/brand,
modern-logo public path, Logo/BrandMark components, #7485 modern default),
then re-applying the legacy-logo removal on top of the new structure:
- delete classic-logo assets and vite copy target
- remove ui.logoStyle setting (backend property, template, config endpoint, admin UI)
- remove logoVariant preference and variant-resolution hooks
- drop manifest-classic.json and classic-logo static handlers/routes
- remove dead classic logo CSS