### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

Adding an AWS Bedrock regional inference profile via the UI (e.g. bedrock/au.anthropic.claude-sonnet-4-5-20250929-v1:0) strips the au. prefix when storing the model. LiteLLM then auto-populates pricing from the us-east-1 registry entry instead of the regional one. Billing is correct (request-time lookup uses the full regional key), but the UI and the cost_breakdown.cache_creation_cost field show wrong-region values.

<img width="2724" height="1142" alt="Image" src="https://github.com/user-attachments/assets/439597a3-f6eb-43e0-811a-9b8cf9adf631" />

### Steps to Reproduce

1. Add a model with litellm_model = bedrock/au.anthropic.claude-sonnet-4-5-20250929-v1:0. Don't enter manual prices. 2. Check the stored record and the model detail page.

**Stored record (note the stripped key):** { "key": "anthropic.claude-sonnet-4-5-20250929-v1:0", "input_cost_per_token": 0.000003, "output_cost_per_token": 0.000015, "cache_creation_input_token_cost": 0.00000375 } **model_map_value resolved at request time (correct):** { "key": "au.anthropic.claude…