Export WithGraphQLFeatures for remote server round tripper implementation

[Copilot]

Summary

Exports WithGraphQLFeatures to enable the remote server to implement custom HTTP round trippers with GraphQL feature flag support.

Why

The remote server needs to set GraphQL feature flags in context for its round tripper (similar to bearerAuthTransport in the local server). Only GetGraphQLFeatures (reader) was exported—withGraphQLFeatures (setter) was not. This prevented proper implementation and testing, causing bugs.

What changed

• Capitalized withGraphQLFeatures → WithGraphQLFeatures in pkg/github/issues.go
• Updated internal call site

MCP impact

• No tool or API changes

Prompts tested (tool changes only)

N/A

Security / limits

• No security or limits impact

Tool renaming

• I am not renaming tools as part of this PR

Lint & tests

• Linted locally with ./script/lint
• Tested locally with ./script/test

Docs

• Not needed

Original prompt

Export WithGraphQLFeatures so that the remote server can implement its own round tripper and test it too, there was already a bug caused by failure to realise the remote server needed a code change also.

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[Copilot]

Pull request overview

This PR exports the WithGraphQLFeatures function to enable the remote server to implement custom HTTP round trippers with GraphQL feature flag support, matching the existing exported GetGraphQLFeatures function.

Changes:

• Renamed withGraphQLFeatures to WithGraphQLFeatures (capitalized to export)
• Updated the function comment to reflect the new export status
• Updated the single internal call site to use the new name