ADR: Persist provider display order independently of configuration

• Status: Accepted
• Related: Issue #587, ADR 0114, ADR 0259

Context

Provider rows are listed in creation order. Users need to move frequently used services ahead of others in settings and model selection menus. Plugin-owned configuration is reconciled from manifests, while list placement is a user preference that must survive reconciliation and restart.

Decision

Rust host-core stores the ordered IDs under the existing kv key providers.order and applies them to providers.list. The additive providers.reorder RPC moves one ID before or after another under the host state lock. The renderer sends a move rather than a replacement list, so an unseen provider created during a drag remains present.

Provider cards use pointer-driven dragging with a live slot preview and edge scrolling. Keyboard moves share the list-order transformation with model ordering. Only completed moves are persisted; failed saves restore the accepted order. Provider fields and default-model selection remain independent of ordering.

Alternatives

• Renderer-only storage would make order depend on which consumer lists providers.
• A sort field in provider configuration would mix user placement with plugin-managed fields and require editing multiple provider records per move.

Consequences

No SQL schema or protocol-version migration is needed. Older clients ignore the metadata. New providers append in creation order; stale saved IDs are ignored. The UI allows whole-card dragging in the AI services list; OAuth account grouping remains separate. Sorting a plugin row does not grant permission to edit its fields.