[KyaClaw]

Summary

Adds missing dex parameter to spot_meta_and_asset_ctxs method, aligning it with other info methods that support DEX-specific queries.

Changes

• Added optional dex: str = "" parameter to spot_meta_and_asset_ctxs method.
• Included "dex": dex in the payload sent to the /info endpoint.

Testing

• Existing test suite passes (where network requests are mocked).
• No breaking changes; default behavior unchanged (empty string DEX).

Fixes #257

[koriyoshi2041]

I rechecked this against the live mainnet /info endpoint today (2026-09-16), and the proposed parameter still appears to be a silent no-op. I sent spotMetaAndAssetCtxs three ways: with no dex, with dex="xyz", and with dex="definitely-invalid-dex". After isolating the non-volatile metadata object (response[0]), all three normalized outputs had the same SHA-256 (3bdf5005b7206faa1acff7eb759a71c6d0991e03fa6ce2074eb75babd3bd3f4c) and the same 501 tokens / 328 universe entries. The full responses differed only because market contexts changed between sequential calls.

That matches the evidence already recorded on #257: HIP-3 partitions perp universes, while spot metadata is global. Adding dex here would therefore advertise filtering the server does not provide. I recommend closing this implementation PR; a docstring note that spot contexts are not dex-scoped would be the accurate alternative.