[BUG] /cost summarises models without version number

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ X ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.59
• Operating System: Ubuntu LTS
• Terminal: Terminator

Bug Description

When typing /cost with an ANTHROPIC_MODEL of claude-sonnet-4@20250514 and ANTHROPIC_SMALL_FAST_MODEL=claude-3-7-sonnet-v2@20250219 cost is summarised 'by model' but only using the family, so I can't see how much each version of model has used, like:

> /cost 
  ⎿  Total cost:            $9.51
     Total duration (API):  18m 17.3s
     Total duration (wall): 3h 14m 54.9s
     Total code changes:    318 lines added, 84 lines removed
     Usage by model:
            claude-sonnet:  463 input, 41.4k output, 15.4m cache read, 1.1m cache write

It would be helpful to split usage by model into truly unique models, rather than the 'family' of model.

Additional Context

I realise using Sonnet 3.7 as the small model seems counterintuitive but if you're in the Vertex EU Regions 3.5 Haiku isn't available - which is quite frustrating!