fix(chat): gpt-6-astra does not use temperature.

[ndbellew]

Summary

Prevents Odysseus from sending the unsupported temperature parameter when using the ChatGPT Subscription provider. This fixes HTTP 400 errors returned by subscription-backed models that reject temperature in the request payload.

Target branch

• This PR targets dev, not main. All PRs land in dev; main is curated by the maintainer at each release. If your PR is on main by accident, click "Edit" on this PR and change the base.

Linked Issue

Fixes #6273

Type of Change

• Bug fix (non-breaking — fixes a confirmed issue)
• New feature (non-breaking — adds new behaviour)
• Breaking change (changes or removes existing behaviour)
• Refactor / cleanup (behaviour unchanged)
• Documentation only
• CI / tooling / configuration

Checklist

• I searched open issues and open PRs — this is not a duplicate.
• This PR targets dev
• My changes are limited to the scope described above — no unrelated refactors or whitespace changes mixed in.
• I actually ran the app (docker compose up) and verified the change works end-to-end.
• I did not run the app/runtime validation and stated that gap in How to Test.

How to Test

1. Configure a ChatGPT Subscription provider in Odysseus and select a model that rejects the temperature parameter.
2. Send a normal chat message and confirm the request completes successfully instead of returning HTTP 400: Unsupported parameter: temperature.
3. Verify non-ChatGPT providers and models that support temperature continue to receive the parameter normally.

Visual / UI changes — REQUIRED if you touched anything that renders

No visual or UI changes were made.

• Screenshot or short clip of the change in the running app, attached below.
• Style match
• No new component patterns
• I am not an LLM agent submitting a bulk PR.

Screenshots / clips

N/A — no UI or rendering changes.

[ndbellew]

🙌🙌