Make Auto model-routing scope, data path, and resolved route explicit

[Hmbown]

Summary

/model auto is currently described in the picker only as “select per turn,” which does not explain its provider, cost, or data-routing scope.

Current behavior

With the DeepSeek router available, Auto can choose a complete provider/model/thinking route from every authenticated provider, not just the active provider. It sends the current request plus a bounded recent-context summary to the router to make that selection.

The product also has distinct concepts named Auto: Auto model route, Auto-Review permission posture, auto-thinking, auto-compaction, and workflow automation. The short label makes these easy to conflate.

User-facing impact

The attached gpt-5.6-sol → GLM-5.2 / api.z.ai transcript matches an explicit persistent provider/model switch rather than the current per-turn Auto status, but the UI does not make this distinction obvious. Users cannot readily tell whether a route change was deliberate, automatic, provider-crossing, or how their prompt was routed.

Recommended behavior

Prefer a provider-scoped default:

• Auto route (this provider) chooses model + thinking only within the active provider.
• A separate explicit opt-in, Auto across connected providers, may choose another authenticated provider.

Before first cross-provider use, clearly confirm:

Auto routing may send a routing summary to DeepSeek and may run this turn through another connected provider. Costs and data policies can differ.

At minimum, if behavior remains unchanged:

• Rename the picker row to Auto route — may use connected providers.
• Add a hint: Chooses provider, model, and thinking per turn. Costs and data policies may vary.
• Show each resolved result in the transcript/footer, e.g. Auto route: Z.ai / GLM-5.2 · classifier: DeepSeek Flash.
• Keep the last resolved route visible in the model picker.
• Distinguish Auto route from Auto-Review, auto-thinking, and auto-compaction in help and settings.

Relevant areas

crates/tui/src/model_inventory.rs, model_routing.rs, tui/auto_router.rs, tui/model_picker.rs, and statusline/model-route copy.