Add GitHub Agentic Workflow for new-issue triage - #1720

Adds an agentic workflow, scaffolded per gh-aw's create.md, that triages newly opened issues. It labels them by type and priority, flags duplicates, asks clarifying questions on unclear reports, and assigns maintainers.

• .github/workflows/issue-triage.md: new workflow, triggered on issues: opened with roles: all so community reports are covered.
  • The agent job is read-only (contents: read, issues: read). All writes go through safe-outputs: add-labels, add-comment, assign-to-user and noop.
  • Type labels are limited to the repo's existing labels: bug, feature, documentation, refactoring, dependencies, question, help wanted, blocked and parked.
  • Priority labels are exactly one of priority: high, priority: medium or priority: low.
  • Duplicates are only linked in the comment. The workflow never closes an issue. It also points out when a report belongs to a separate adapter or middleware gem.
  • Unclear reports get question plus 1–3 specific questions about versions, adapter and reproduction.
  • Assignment only happens for actionable issues. It is restricted to an allowlist and blocks bots.
• .gitattributes: marks *.lock.yml as generated, as create.md requires.

Needs attention before merge:

• Missing lock file. gh aw couldn't be installed in the authoring environment (GitHub release download returned 403). Run gh aw compile issue-triage and commit the resulting issue-triage.lock.yml. The frontmatter has not been checked against the compiler.
• Priority labels don't exist yet. The repo has none. create-if-missing: true makes the workflow create them on first use. Alternatively, create them with descriptions up front, or drop priority from the workflow.
• Assignee allowlist is a placeholder. iMacTia and olleolleolle are guesses, because I couldn't read the collaborator list. Please correct assign-to-user.allowed and the routing rules in the prompt.