Gateway: updatable provider/model catalog file

[gregjkal]

Summary

Consolidate all knowledge of paid providers and their models into one data file that Gateway can check for updates against and download, so new models (for example GPT-6-Astra) can be pushed without a Gateway release.

Details

From the #cppa-wg21-org design discussion on 2026-09-09:

• One file describing each closed-weight provider: name, endpoint, wire protocol, model families and versions, API key variable name.
• Gateway gains a "check for updates" action that fetches the latest version of this file.
• Not Lua. Gateway does not run Lua, so this should be a plain data format (TOML or JSON, TBD).
• The Remote tab UI (Gateway: closed-weight frontier provider catalog with per-provider API key UI #24) and the installer's gateway.env template (Installer: create gateway.env pre-populated with empty provider key variables #26) should both be driven by this file.

Related

• Provider catalog UI: Gateway: closed-weight frontier provider catalog with per-provider API key UI #24
• gateway.env template: Installer: create gateway.env pre-populated with empty provider key variables #26