[Cosmos]: Adding Semantic Reranker API

[aayush3011]

Description

This PR adds semantic reranking functionality to the Azure Cosmos DB Python SDK, enabling developers to leverage document reranking capabilities directly from their Cosmos DB containers.

Core Implementation

• New semantic_rerank() method on ContainerProxy class for performing semantic reranking operations
• Dedicated inference pipeline to communicate with Azure's inference service
• Custom authentication policy InferenceServiceBearerTokenPolicy that preserves standard Bearer token format needed for Inference service.

API Design

• Public Method: ContainerProxy.semantic_rerank() - Developer-facing API
• Internal Method: CosmosClientConnection.SemanticRerank() - Handles pipeline communication
• Infrastructure: _SemanticReranker class manages endpoint construction and pipeline setup

Example usage

results = container.semantic_rerank(
    reranking_context="What is the capital of France?",
    documents=[
          "Berlin is the capital of Germany.",
          "Paris is the capital of France.",
          "Madrid is the capital of Spain."
    ],
    semantic_reranking_options={
        "return_documents": True,
        "top_k": 10,
        "batch_size": 32,
        "sort": True
    }
)

Result

{
  "Scores": [
    {
      "index": 1,
      "document": "Paris is the capital of France.",
      "score": 0.9921875
    },
    {
      "index": 2,
      "document": "Madrid is the capital of Spain.",
      "score": 0.0024719238
    },
    {
      "index": 0,
      "document": "Berlin is the capital of Germany.",
      "score": 0.001411438
    }
  ],
  "latency": {
    "data_preprocess_time": 1.9073486e-06,
    "inference_time": 0.021552563,
    "postprocess_time": 1.1920929e-06
  },
  "token_usage": {
    "total_tokens": 405
  }
}

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull Request Overview

This PR adds semantic reranking functionality to the Azure Cosmos DB Python SDK, enabling developers to leverage document reranking capabilities directly from their Cosmos DB containers by integrating with Azure's inference service.

• Implements a new semantic_rerank() method on the ContainerProxy class for performing semantic reranking operations
• Creates a dedicated inference pipeline with custom authentication to communicate with Azure's inference service
• Adds comprehensive test coverage for the new semantic reranking functionality

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
azure/cosmos/container.py	Adds the public semantic_rerank() method to ContainerProxy class
azure/cosmos/_semantic_reranker.py	Core implementation of semantic reranking client with inference pipeline
azure/cosmos/_inference_auth_policy.py	Custom Bearer token authentication policy for inference service
azure/cosmos/_cosmos_client_connection.py	Integrates semantic reranker into client connection infrastructure
tests/test_semantic_reranker.py	Test suite for semantic reranking functionality

[github-actions]

API Change Check

APIView identified API level changes in this PR and created the following API reviews

azure-cosmos

[Pilchie]

Looks fine to me so far.

[aayush3011]

/azp run python - cosmos - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[simorenoh]

Just some small questions and changes, thanks Aayush!

[raj-shah14]

Looks good to me

[aayush3011]

/azp run python - cosmos - ci

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[xinlian12]

@sdkReviewAgent-2