step-03-create-issue: Host-Aware Tracking Idempotency

step-03-create-issue is documented in the reference section:

• Step 03 Host-Aware Tracking Idempotency
• Provider-Aware Workflow Prep Reference

The current contract is host-aware:

Host type	Tracking path
github	GitHub issue reuse, search, create, and label setup through gh
azdo	Azure Boards reuse/create, with structured local metadata fallback
other	Structured local metadata only

GitHub issue and label commands are valid only in the github branch. Azure DevOps and unsupported remotes never fall through to gh issue or gh label commands.