Removes the redundant JSON array parsing.

[tommie]

Adds Jest as a test framework and tests for JSON parsing.

Closes #646.

[Copilot]

Pull Request Overview

This PR adds Jest-based unit testing infrastructure to the project and modifies the toolkit initialization to be lazy-loaded. The changes enable proper testing of utility functions that previously required GitHub Actions environment variables at module load time.

Key changes:

• Converted toolkit initialization from eager to lazy loading to support testing
• Removed redundant JSON parsing step from parseInputArray (YAML parser handles JSON)
• Added Jest testing framework with configuration and CI integration

Reviewed Changes

Copilot reviewed 5 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tsconfig.json	Changed rootDir to "." to support compiling test files
src/util.ts	Refactored toolkit to lazy initialization and simplified parseInputArray to only use YAML parser
test/util.test.ts	Added unit tests for parseInputArray function with environment setup
package.json	Added jest dependencies and updated test scripts
jest.config.js	Added Jest configuration for ts-jest
.husky/pre-commit	Added test execution to pre-commit hook
.github/workflows/test.yml	Added CI test job

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.