feat: Modernize from CoffeeScript/Gulp to ES6/Rollup/Jest

[nmccready]

Summary

Complete modernization of angular-simple-logger while preserving backward compatibility.

Changes

Source Code

• CoffeeScript → ES6 JavaScript — all source files converted
• src/logger.js — Logger class with level filtering, spawn support
• src/module.js — Angular module registration (nemLogging)
• src/index.js — Full version with debug integration
• src/index.light.js — Light version without debug dependency

Build System

• Gulp → Rollup — modern bundler with tree-shaking
• Output: UMD + ESM bundles for both full and light versions
• Minified builds included
• dist/ removed from git (built on publish)

Tests

• Karma/Jasmine → Jest (62 tests passing)
• Unit tests for Logger class (level filtering, doLog, spawn, validation)
• Integration tests with angular-mocks (service, provider, decorator)
• Debug namespace tests (spawn with namespace, enable/disable)
• Array.prototype extension safety test

CI/CD

• GitHub Actions replacing Travis CI
  • tests.yml — Node 18/20/22 matrix
  • publish.yml — npm publish with OIDC provenance on release
  • release.yml — manual workflow dispatch for version bumps

Package

• debug upgraded to v4 (from v2)
• angular moved to peerDependencies
• Modern exports field with subpath for light version
• module field for ESM bundlers

Removed

• Travis CI, Bower, CoffeeScript tooling, Karma, PhantomJS
• Gulp and all gulp tasks
• Old dist files from git

What is NOT changed

• Public API: nemLogging module name, nemSimpleLogger, nemDebug
• AngularJS 1.x target (not upgrading to Angular 2+)
• Log levels and filtering behavior
• Spawn behavior (both object and namespace modes)
• Decorator pattern

Migration

# Before (bower)
bower install angular-simple-logger

# After (npm)
npm install angular-simple-logger

Import paths:

// Full version (with debug)
import "angular-simple-logger";
// or
require("angular-simple-logger");

// Light version (no debug)
import "angular-simple-logger/light";