fix(shipping): use GitHub dequeue input id

[alex-overcyai]

Queued PR cancellation fails because the GraphQL request supplies pullRequestId, but DequeuePullRequestInput requires id. Use id for dequeue while retaining pullRequestId for disabling auto-merge. Continue passing the PR node ID and preserve every revision check and readback.

Strengthen the transport and CLI fakes so they reject the invalid field. The targeted suite passes 28 tests. Restoring the old production request fails both new guards. Typechecking passes, and an independent reviewer reproduced the green and mutant runs with no findings.

The broader watcher suite reports 185 passes and an unchanged transport deadline test failing because its PID file is missing. That separate failure remains unresolved; this PR does not claim the full suite passes.

Contract verified against GitHub's current input schema and live schema introspection.

[michael-denyer]

Thanks for this, @alex-overcyai. The field name had been wrong since the code landed in September, and the schema link in your description made it quick to confirm against live introspection. Merged as fee271b.

#240 follows up on the tests and is merged too. Both shipping test files now call one fake of gh api graphql that keeps each mutation's required input field in a table. It replaces the two string checks added here, so the tests also catch the same mistake on disablePullRequestAutoMerge, and a query that differs only in spacing no longer fails them.