Add support for more timeouts to Nexus operations

[Quinn-With-Two-Ns]

Add schedule-to-start and start-to-close for Nexus operations

NOTE, before this can be merged the API still needs to be tagged, core changes need to be merged and tests need to be added

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Note

Medium Risk
Touches workflow command construction for Nexus operations; incorrect mapping could change timeout behavior or break compatibility with older servers, though coverage is added via new/updated timeout tests.

Overview
Adds ScheduleToStartTimeout and StartToCloseTimeout to NexusOperationOptions and wires them through WorkflowInstance.StartNexusOperationAsync so Nexus operation scheduling can enforce these server-side timeouts (in addition to the existing schedule-to-close).

Extends Nexus worker tests to assert the correct TimeoutType surfaces for schedule-to-close, schedule-to-start, and start-to-close failures, and bumps the local test dev-server download version to pick up the required server support.

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

[cretz]

Pedantic, but can we move all but the first line of these three docs into a <remarks> section instead?

[Quinn-With-Two-Ns]

Done, let me know if it looks right

[jmaeagle99]

Remarks should not be nested within summary but be a sibling.

[Quinn-With-Two-Ns]

Ah thanks, fixed

[cretz]

LGTM. Merged main and will merge after CI (may be tomorrow)