Plugin System

• ✅ Integrated full plugin system into bot.py
• ✅ Created entry-point based plugin discovery
• ✅ Added example plugin in examples/ directory
• ✅ Created all documentation (README, PLUGIN_DEVELOPMENT, CHANGELOG)
• ✅ Set up GitLab CI/CD with plugin installation
• ✅ Added both entry-point and drop-in plugin support

Summary by CodeRabbit

• New Features

  • Introduces a pluggable plugin system with discovery, startup loading, and hot reload.
  • Adds Discord commands: /plugins and /reload_plugin.
  • Adds API endpoints: GET /plugins and POST /plugins/{name}/reload.
  • Includes an example plugin and support for drop-in local plugins.
  • Adds a default plugin configuration file.

• Documentation

  • Comprehensive plugin system docs, development guide, example plugin README, and a new CHANGELOG.

• Chores

  • CI now installs the examples package in editable mode.
  • Adds setuptools as a dependency.