docs(providers): Poolside Platform inference shuts down 2026-10-31 (per user report) — update provider note and free catalog

Summary

A discussion (#17281) reports that platform.poolside.ai shows a banner saying Poolside Platform inference will shut down on 31 October 2026 (models downloadable from Hugging Face). OmniRoute ships poolside as a built-in provider with a free-tier note, so it will stop being usable after that date if the banner is accurate.

Current state

• src/shared/constants/providers/apikey/inference-hosts.ts → poolside (inference.poolside.ai), hasFree: true, note "Laguna S 2.1 and XS 2.1 are free during Preview".
• Registry entry open-sse/config/providers/registry/poolside/index.ts.
• Poolside-named models also appear under other gateways (kilo-gateway free list in open-sse/config/freeModelCatalog.data.ts, cline, nvidia, nara comments).

Not verified

• The banner itself (I only saw a user's screenshot, not a Poolside announcement page).
• Whether the models listed under Kilo Gateway, Cline or NVIDIA depend on Poolside's own inference, so they must not be assumed to disappear.

Proposal

After confirming the shutdown from a Poolside source: update the provider's note (and mark it as ending/discontinued with the date), remove or flag its free-catalog entries, and follow docs/reference/REMOVED_PROVIDERS.md rules only if the provider is actually removed (not required for a shutdown by the provider itself).

Acceptance

• Poolside source for the shutdown date recorded.
• Provider note and free catalog updated; docs/counts checks green.

Refs discussion #17281