[BUG][bedrock] /model picker's Haiku 4.5 quick-pick writes bare alias "claude-haiku-4-5" -> 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 (CLAUDE_CODE_USE_BEDROCK=1), selecting "Haiku 4.5" from the /model picker fails every request with:

API Error (claude-haiku-4-5): 400 The provided model identifier is invalid.

The picker persists the bare catalog alias claude-haiku-4-5 instead of resolving it to the region-prefixed, dated Bedrock inference-profile ID. Note this is missing both the region prefix (eu.anthropic. / us.anthropic.) and the date suffix (-20251001-v1:0) - worse than the Opus 4.8 case in #68005, which is only missing the region prefix.

Every other Haiku-selection path in the same setup works correctly, because each of them already uses the full ID:

• settings.json top-level "model": "eu.anthropic.claude-haiku-4-5-20251001-v1:0" - works
• CLAUDE_CODE_SUBAGENT_MODEL=eu.anthropic.claude-haiku-4-5-20251001-v1:0 - works
• Agent tool model: "haiku" shorthand for subagents - works (resolves correctly there)

So this looks isolated to the interactive /model picker's built-in "Haiku 4.5" quick-pick entry for the main session model specifically.

What should happen

/model should persist the Bedrock-qualified model ID when the active provider is Bedrock, same as every other selection path already does.

Workaround

Type the full ID directly instead of using the picker's quick-pick row:

/model eu.anthropic.claude-haiku-4-5-20251001-v1:0

Prior art

This looks like the same underlying bug class as #68005 (Opus 4.8 [1m], missing region prefix only) and the earlier Opus 4.6/4.7 regressions referenced there (#23499 closed, #61495 open). Each new model release seems to re-introduce this because the picker's ID resolution doesn't account for the Bedrock prefix/date-suffix requirements. Filing separately since it's the Haiku 4.5 entry and the failure mode is slightly different (missing both prefix and suffix, not just prefix).

Error messages/logs

API Error (claude-haiku-4-5): 400 The provided model identifier is invalid.

Claude model

Haiku 4.5

Is this a regression

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

Claude Code version

2.1.209

Platform

AWS Bedrock

Operating system

macOS