match_dense crashes on non-string knn_params values (embedded + thrift SDKs)

What happened?

match_dense lowercases every knn_params value assuming it is a string, so a natural call with a numeric option crashes:

table.match_dense("v", [1.0, 2.0], "float", "l2", 5, {"ef": 200})
# AttributeError: 'int' object has no attribute 'lower'

This affects three call sites: the embedded SDK's match_dense, the thrift SDK's match_dense, and the thrift SDK's _handle_fde_match_dense. Every other match_* method formats option values without assuming str, and the HTTP SDK passes them through untouched.

Reproduced on current main (eca7266) for both SDKs.

Expected behavior

Non-string option values are accepted and stringified, so {"ef": 200} behaves the same as {"ef": "200"}.

Versions

• infinity, current main (eca7266)
• python/infinity_embedded/local_infinity/query_builder.py, python/infinity_sdk/infinity/remote_thrift/query_builder.py

Start in python/infinity_embedded/local_infinity/query_builder.py and python/infinity_sdk/infinity/remote_thrift/query_builder.py, examining match_dense in both SDKs and the thrift _handle_fde_match_dense entry point. Reproduce the issue with a numeric ef value, then verify that numeric and string option values behave equivalently across all three call sites.