### Check for existing issues

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

### What happened?

When using azure_ai/model_router/..., LiteLLM correctly returns the actual selected model in the API response, but /spend/logs stores the router deployment model instead.

Example:

- actual response model: - azure_ai/gpt-5.4-mini-2026-03-17 - spend log stored model: - azure_ai/model_router/model-router

This makes spend logs inconsistent with the user-facing response and hides which Azure model was actually selected by Azure Model Router.

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LiteLLM Version

Observed on:

- ghcr.io/berriai/litellm-database:main-v1.83.14-stable

Also traced in source history in local clone.

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Expected Behavior

For Azure Model Router requests, /spend/logs should store the same effective model that LiteLLM preserves in the response / standard logging flow, e.g.:

```json { "model": "azure_ai/gpt-5.4-mini-2026-03-17" } ```

model_map_information can still point to:

…