* test: move key-gated tests/test_litellm SDK tests into tests/llm_translation and drop empty folders
* test: make token counter and health check unit tests run offline
* ci: point unit shards, rust path filter, Makefile and docs at tests/unit
* docs: fix stale test_litellm run paths in moved llm_translation tests
* fix: correct databricks e2e sys.path depth and contributing example path
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Co-authored-by: yuneng <yuneng@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
- Add OAuth M2M (Machine-to-Machine) authentication via DATABRICKS_CLIENT_ID and DATABRICKS_CLIENT_SECRET
- Add Databricks SDK auto-auth with automatic credential discovery
- Add sensitive data redaction for secure logging (tokens, API keys, secrets)
- Add custom user_agent parameter for partner attribution in Databricks telemetry
- Support user_agent in LiteLLM Proxy via config.yaml litellm_params
- Add 49 mocked unit tests for all new functionality
- Add 13 E2E tests for real-world validation (skipped in CI)
- Update documentation with new features and examples
