#3531 [GUI] Share Official App Contracts With Optional Tray And Web Companions

本文

### Area

GUI

### What do you want to do?

Keep optional Tray and browser companions aligned with the installed official App after an App or Control update. Companions should read the App's real Model Catalog, recommendations, Context choices and idle-setting bounds instead of maintaining separate versions of them. A browser surface should reuse the unmodified official App frontend and detect when its copied assets no longer match the installed App/Control contract.

### What do you do today instead?

A private integration reads the installed App/Control metadata and freezes its official frontend into a verified candidate. It was exercised with App 0.2.1, Control 0.1.46.3 and Engine 0.1.46 on Windows. The private gateway's account, deployment and external-client synchronization are site-specific; those are not proposed as Strata core features.

### Proposed scope for maintainer agreement

One opt-in offline tool under `tools/app-surface-contract/`:

- Read the selected official App/Control's existing `strata_models` metadata and native idle-setting schema. Keep Reasoning Effort in the official Composer and update installation in the official App.
- Emit a versioned, allowlisted compatibility snapshot with source fingerprints. Unknown App versions or changed contracts need validation, without mutating the installed App or current model.
- Export and verify byte-identical official App Web assets in a new directory, binding the complete inventory and shared App/Control fingerprint to a manifest. This is a candidate, not an updater or production deployment.

The default App, engine, server, setup, updater and installer paths remain unchanged. The helper does not start an engine or Web host, add a daemon, manage credentials or implement another effort selector. Existing optional Tray #3365 and Local Model Extension #3373/#3369 retain their separate scope.

Would this small shared export/verification boundary be useful to companion authors? A draft implementation will be supplied for inspection at the user's request; no maintainer agreement or future compatibility is assumed. Anonymous screenshots show the reused official UI, not hardware performance or GPU validation.