Upgrade linting and formatting configuration with new npm scripts

[Copilot]

This PR modernizes the project's linting and formatting setup by upgrading to the latest versions of @electerious/eslint-config and adding @electerious/prettier-config for consistent code formatting.

Changes Made

Dependencies

• Upgraded @electerious/eslint-config from 4.1.0 to 5.1.0
• Added @electerious/[email protected] for code formatting
• Added [email protected] as a dev dependency

Configuration

• Created eslint.config.js to support the new ESLint v9 flat configuration format
• Added prettier configuration to package.json
• Removed legacy ESLint configuration from package.json

NPM Scripts

Updated the npm scripts to match modern development workflows:

• "eslint": "eslint \"**/*.js\"" - Run ESLint on all JavaScript files
• "format": "npm run eslint -- --fix && npm run prettier -- --write" - Auto-fix linting issues and format code
• "lint": "npm run eslint && npm run prettier -- --check" - Check both linting and formatting
• "prettier": "prettier --ignore-path .gitignore \"**/*.{js,json,md,yml}\"" - Format multiple file types
• "test": "npm run lint && node --test" - Run linting and tests using Node.js built-in test runner

Testing

• Migrated from Mocha/Chai to Node.js built-in test runner
• Updated test assertions to use Node.js assert module
• Maintained existing test functionality while modernizing the testing approach

Code Formatting

All code has been automatically formatted using the new Prettier configuration, ensuring consistent code style throughout the project including:

• Updated JSDoc type annotations (String → string, Object → object)
• Consistent spacing and indentation
• Modern JavaScript patterns (globalThis.window instead of window)

The changes maintain backward compatibility while providing a more modern development experience with better tooling integration.

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