feat: add rerank_depth_start parameter to search()

[vicilliar]

Summary

• Adds rerank_depth_start: Optional[int] = None parameter to Index.search()
• Serialises as rerankDepthStart in the Marqo API request body
• Follows the same pattern as rerank_depth / rerankDepth
• None value is omitted from the request body (existing behaviour preserved)

Server-side PR: marqo-ai/marqo#1393

Test plan

• test_rerank_depth_start_serialized_as_camel_case — verifies correct key name in request body
• test_rerank_depth_start_none_omitted_from_body — verifies None is not sent
• test_rerank_depth_start_zero_included_in_body — verifies 0 (falsy but valid) is sent

🤖 Generated with Claude Code

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Note

Low Risk
Low risk: adds an optional search parameter that is omitted when None, with unit tests covering serialization and the 0 edge case.

Overview
Adds a new optional rerank_depth_start parameter to Index.search() and serializes it to the API as rerankDepthStart, enabling reranking/score modifiers to apply only to a specified slice of the top rerank_depth results.

Includes unit tests that mock the HTTP layer to verify camelCase serialization, omission when None, and inclusion when set to 0 (falsy but valid).

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