[Bug]: the *Claude provider surfaces the *selected* model, not the served* model. silent Fable 5 → Opus guardrail fallback is invisible

[snipemanmike]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

use fable 5
profit?

Expected behavior

A turn is attributed to the model that actually produced it. If a server-side guardrail fallback swaps Fable 5 → Opus, T3 Code should reflect Opus for that turn or at minimum flag that the served model differs from the selected one.

Actual behavior

The thread keeps showing the selected model (Fable 5). The served model is never surfaced, so an Opus fallback is silent.

Impact

Major degradation or frequent failure

Version or commit

v0.0.28-nightly.20260610.520 @ 0b40ea6

Environment

No response

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

No response