[BUG][bedrock] /model picker's Fable 5.1 quick-pick writes wrong Bedrock ID -> 400 invalid model identifier

Preflight checklist

• [x] I searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's wrong

On a Bedrock-backed setup (EU region), selecting the "Fable" entry from the /model picker fails every request with:

API Error (eu.anthropic.claude-fable-5): 400 The provided model identifier is invalid.. Try /model to switch to eu.anthropic.claude-opus-5[1m].

The picker's quick-pick entry is labeled "Fable 5" (not "Fable 5.1", the current release) and persists eu.anthropic.claude-fable-5 as the model ID. That ID is wrong on two counts:

• It's missing the -1 point-release suffix.
• There is no eu.-prefixed inference profile for this model; the valid Bedrock forms are unprefixed, us., and global..

Confirmed via a separate Bedrock-backed client (Pi) against the same AWS account: anthropic.claude-fable-5-1, us.anthropic.claude-fable-5-1, and global.anthropic.claude-fable-5-1 are all valid and reachable. So the model is live on Bedrock in this account/region — the picker's ID resolution is what's broken, not availability.

What should happen

/model's Fable quick-pick should show "Fable 5.1" and persist a valid Bedrock-qualified ID (e.g. global.anthropic.claude-fable-5-1), the same way other model families already resolve correctly.

Steps to reproduce

1. Configure Claude Code for Bedrock, EU region.
2. Run /model and select the Fable entry.
3. Send any message.

Workaround

Type the full ID directly instead of using the picker's quick-pick row (same workaround pattern confirmed for this bug class in #89501):

/model global.anthropic.claude-fable-5-1

Prior art

Same underlying bug class as #89501 (Haiku 4.5 quick-pick writes a bare, unqualified alias) and #92924 (Opus [1m] round-trip breaks the picker list). Each new model release seems to re-introduce this because the picker's ID resolution doesn't account for Bedrock's region-prefix/version-suffix requirements.

Error messages/logs

API Error (eu.anthropic.claude-fable-5): 400 The provided model identifier is invalid.. Try /model to switch to eu.anthropic.claude-opus-5[1m].

Claude model

Fable 5.1

Is this a regression

Unclear - haven't confirmed a prior working version for this specific picker entry.

Claude Code version

2.1.274

Platform

AWS Bedrock

Operating system

macOS