fix: Align GraphQL agent assignment API with GitHub specification

[Copilot]

The GraphQL mutation for assigning Copilot agents to issues used incorrect parameter and field names that didn't match GitHub's official API specification from the December 3, 2025 changelog.

Changes

• GraphQL mutation parameter: copilotAssignmentOptions → agentAssignment
• Input type: CopilotAssignmentOptionsInput → AgentAssignmentInput
• Field name: baseBranch → baseRef

Before

const extendedMutation = `
  mutation($assignableId: ID!, $actorIds: [ID!]!, $copilotAssignmentOptions: CopilotAssignmentOptionsInput) {
    replaceActorsForAssignable(input: {
      assignableId: $assignableId,
      actorIds: $actorIds,
      copilotAssignmentOptions: $copilotAssignmentOptions
    })
  }
`;

After

const extendedMutation = `
  mutation($assignableId: ID!, $actorIds: [ID!]!, $agentAssignment: AgentAssignmentInput) {
    replaceActorsForAssignable(input: {
      assignableId: $assignableId,
      actorIds: $actorIds,
      agentAssignment: $agentAssignment
    })
  }
`;

Updated assign_agent_helpers.cjs, assign_to_agent.cjs, and test files. Recompiled all workflows with corrected implementation.

Reference: community/community#173575 (comment)

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[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/community/community/discussions/173575/comments
  • Triggering command: /usr/bin/curl curl -s REDACTED (http block)
• https://api.github.com/user
  • Triggering command: /usr/bin/gh gh api user --jq .login g_.a GO111MODULE ache/node/24.11.1/x64/bin/npm GOINSECURE parser GOMODCACHE go env _35oYNQDJ GO111MODULE (http block)
  • Triggering command: /usr/bin/gh gh api user --jq .login -json GO111MODULE /opt/hostedtoolcache/go/1.25.0/x64/bin/go GOINSECURE GOMOD GOMODCACHE go env -json GO111MODULE 1/x64/bin/node GOINSECURE dabbd6fc6212d3d1api GOMODCACHE 5930172/b332/fil--jq (http block)
  • Triggering command: /usr/bin/gh gh api user --jq .login '**/*.cjs' '**/*.ts' '**/*.json-- GO111MODULE b3c4192ac12a6189a5dd2cc0790905a13bf/log.json GOINSECURE GOMOD GOMODCACHE sh -c ns/setup.git GOPROXY e/git-remote-https GOSUMDB GOWORK g/node_modules/.moby e/git-remote-htt-address (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)