Add ready-for-dev issue and PR readiness gates

[neubig]

Add a repository-appropriate ready-for-dev workflow and CI enforcement.

Scope:

• Add type-specific readiness checks for bugs and enhancements, tailored to the TypeScript client (reproducible JavaScript/TypeScript/package-manager commands such as npm, pnpm, yarn, or npx).
• Ensure not-ready results do not fail the workflow under set -euo pipefail; JSON output must drive label and comment behavior.
• Add idempotent readiness feedback comments.
• Add a PR description gate for linked issues and refresh it when ready-for-dev changes.
• Add tests using the repository’s existing Node/TypeScript test tooling.

Acceptance criteria:

• Not-ready issues still receive readiness feedback and 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.