fix: preserve structured errors in paginated methods

[aproskill81]

Summary

Preserves structured API error responses in paginated client methods instead of failing with a secondary runtime error during response aggregation.

What changed

• stop paginated collection methods from spreading response.data when the response is an error object
• preserve the existing structured error contract returned by the HTTP helpers
• align affected TypeScript return types with the actual runtime behavior
• add coverage for paginated error handling

Why

The client already returns structured error objects from HTTP helpers. Some paginated methods were inconsistent with that pattern and could throw a secondary runtime error instead of returning the original API error.

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Note

Medium Risk
Changes public return types and runtime behavior of several paginated client methods to return error objects instead of throwing during aggregation, which may require downstream callers to handle unions.

Overview
Fixes paginated collection methods to preserve structured HTTP error responses instead of attempting to spread non-array response.data and throwing a secondary runtime error.

Adds a shared getPaginatedResponseData guard and updates several methods (e.g. getTrades, getOpenOrders, rewards earnings/rewards fetchers) to return ... | ClobErrorResponseBody when pagination responses are error-shaped. Expands ClobErrorResponseBody typing and adds Vitest coverage ensuring paginated methods return { error, status } unchanged on failures.

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