[Activity] Use coding agent with proper setup

Set up a GitHub workflow for the coding agent to have all necessary tooling in its environments.
[Docs](https://docs.github.com/en/copilot/how-tos/use-copilot-agents/coding-agent/customize-the-agent-environment)

Read the linked GitHub Copilot coding-agent customization documentation first, then inspect this repository's existing workflow configuration to identify environment setup conventions. Done means a workflow provides the coding agent with the necessary repository tooling, but the issue does not name the tooling or a validation test.

Written by the indexing model from the issue text.