GitLab

There are two etcd keys:
- The service
- The model

The second one is the interesting one for us. Previously we confused the two.

Replaces hard-coded "kv-hit-rate" string in multiple places with KV_HIT_RATE_SUBJECT constant in lib/llm.

Co-authored-by: Graham King <grahamk@nvidia.com>

Co-authored-by: Ryan Olson <rolson@nvidia.com>

This means we don't need to explain the parts to the users until they are ready. We use what they provide and default the rest.

Allows all of this and more:
- `tio out=tdr://test`
- `tio out=tdr://llama_8b_pool`
- `tio in=tdr://corp_ai_research_group/model_next-20250226`
- `tio out=tdr://AIRE.NIM.migrate.mistralrs.1802`

Python, API, etc all untouched.

Co-authored-by: aflowers <aflowers@nvidia.com>

Signed-off-by: Neelay Shah <neelays@nvidia.com>
Co-authored-by: Ryan McCormick <rmccormick@nvidia.com>