Implement read-only unified settings providers

[55515-code]

Goal

Implement the first read-only adapter for profiles/settings-registry-v1.json using upstream batocera-controlcenter components.

Scope

Render Home, Network, Controllers, Storage, Updates, and Recovery state without enabling mutation or arbitrary shell actions.

Acceptance criteria

• Typed provider responses have stable error and unavailable states.
• UI runs unprivileged and remains controller, touch, and keyboard navigable.
• Layout is tested at 1280x800 and a TV viewport.
• Provider/API compatibility failures disable pages cleanly.

[Deniwn22]

Good catch. This is related to the RFC change in how trailing slashes are normalized. PR incoming.

[55515-code]

Archived after the LuigiOS architecture transition merged in #11. The Batocera/Steam Deck/Plasma assumptions in this issue no longer describe the product on main. Current work targets the CachyOS/COSMIC developer workstation, transactional recovery, and rootless SDK. See #12 and the current roadmap for active contribution lanes. This issue remains public as historical context; it is not an active commitment.