feat: add organization issue fields sync support

[joshjohanning]

Summary

Adds support for syncing organization issue fields configuration, aligned to the GitHub issue-fields REST API.

What changed

• Added new action inputs:
  • issue-fields-file
  • delete-unmanaged-issue-fields
• Added org-level override support in orgs.yml:
  • issue-fields
  • issue-fields-file
  • delete-unmanaged-issue-fields
• Implemented issue-fields parsing, normalization, merge, compare, and sync logic
  • Uses GET/POST/PATCH/DELETE /orgs/{org}/issue-fields
  • Validates enum option colors (gray|blue|green|yellow|orange|red|pink|purple)
  • Preserves existing single-select option ids on PATCH when names match
  • Treats data_type changes as incompatible in-place updates
• Added docs and sample config updates (README.md, sample-configuration/orgs.yml, new sample-configuration/issue-fields.yml)
• Added Jest coverage for validation, parsing, merge, sync behavior, and run() wiring

Rollout note

Issue fields are still gated/rolling out by organization preview. For orgs without access, the action handles 403/404 as a warning and skips issue-fields sync.

This PR is intentionally Draft until we can validate end-to-end on an org with issue-fields enabled.

[Copilot]

Pull request overview

This PR extends the bulk org settings sync GitHub Action to support syncing organization issue fields via the GitHub REST API, including new inputs, per-org overrides, parsing/normalization, sync logic, docs, samples, and Jest coverage.

Changes:

• Added new action inputs and per-org override keys for issue-fields configuration (including optional deletion of unmanaged issue fields).
• Implemented issue-fields YAML parsing/normalization, merge-by-name behavior, comparison logic, and create/update/delete sync against /orgs/{org}/issue-fields.
• Updated documentation, sample configurations, and bumped package version (with lockfile + coverage badge updates).

Show a summary per file

File	Description
src/index.js	Adds issue-fields config keys, parsing/normalization, merge/compare, and org sync execution logic.
action.yml	Introduces issue-fields-file and delete-unmanaged-issue-fields inputs.
README.md	Documents issue-fields syncing behavior, inputs, permissions, and per-org override semantics.
sample-configuration/orgs.yml	Adds sample per-org inline and file-based issue-fields configuration.
sample-configuration/issue-fields.yml	New standalone sample file for issue-fields definitions.
tests/index.test.js	Adds Jest coverage for issue-fields validation, parsing, merging, sync behavior, and run() wiring.
package.json	Bumps version and adds keyword for issue-fields.
package-lock.json	Updates lockfile version metadata to match package version bump.
badges/coverage.svg	Updates coverage badge after test/coverage changes.

Copilot's findings

• Files reviewed: 7/9 changed files
• Comments generated: 1

[github-actions]

📦 Draft Release Created

A draft release v1.12.0 has been created for this PR.

🔗 View Draft Release

Next Steps

• Review the release notes
• Publish the release to make it permanent

This is an automated reminder from the publish-github-action workflow.