Add nano agentic workflow

[mrjf]

Summary

• replace the plain nano GitHub Actions workflow with a real gh-aw Agentic Workflow source and compiled lockfile
• ask the local Qwen/Ollama OpenAI-compatible endpoint for one plain-text response
• stage that response as a create_issue safe-output item so the AWF safe_outputs job creates the issue

Validation

• gh aw compile nano --validate --approve
• bash scripts/patch-local-qwen-awf-pricing.sh .github/workflows/nano.lock.yml
• gh aw validate nano --no-check-update
• /opt/homebrew/bin/actionlint .github/workflows/nano.lock.yml
• bash -n scripts/patch-local-qwen-awf-pricing.sh scripts/check-gh-aw-runner.sh scripts/smoke-local-openai-compatible.sh
• git diff --check