Add ready-for-dev issue and PR readiness gates

[neubig]

Add a repository-appropriate ready-for-dev workflow and CI enforcement for skills, integrations, and automations.

Scope:

• Add type-specific readiness checks for bugs and enhancements, tailored to extension contributions and reproducible Python/package or validation commands.
• Ensure not-ready results do not abort workflow processing under set -euo pipefail.
• Add idempotent readiness feedback comments and label management.
• Add a PR description gate for linked issues and refresh it when ready-for-dev changes.
• Add tests using the repository’s existing Python test tooling.

Acceptance criteria:

• Not-ready issues still receive feedback and correct label updates.
• Linked PRs are blocked until their issue is ready.
• Label transitions refresh linked PR checks.
• CI and tests pass.

This issue was created by an AI agent (OpenHands) on behalf of the user.

[neubig]

Draft PR #509 implements the ready-for-dev gates:

• .github/workflows/issue-readiness-check.yml manages the ready-for-dev label with type-specific criteria tailored to extension contributions (bugs: reproducible command such as uv run pytest/npm run in Actual Behavior plus an Acceptance Criteria checklist; enhancements: Desired Behavior plus checklist).
• Not-ready results never abort the workflow under set -euo pipefail (JSON mode always exits 0), so label updates and the idempotent, marker-upserted feedback comment still run.
• .github/workflows/pr-description-check.yml blocks non-draft PRs until linked issues carry ready-for-dev (pre-rollout issues grandfathered), and label transitions re-run the gate on linked open PRs via refresh_linked_pr_checks.py.
• 32 new pytest tests cover all three scripts; full suite (768 passed) and all PR checks are green.

This comment was created by an AI agent (OpenHands) on behalf of the user.