Feat/franceconnect v2

[moustachu]

This pull request introduces several upgrades and enhancements across the codebase, focusing on dependency updates, improved environment configuration, and enhancements to the Omniauth FranceConnect integration. The most significant changes include updating Ruby, Rails, and Node.js versions, improving Omniauth support for FranceConnect with new configuration options and UI enhancements, and adding more flexible environment variable management.

Dependency and Environment Updates:

• Upgraded Ruby from 2.6.5 to 2.6.9, Rails from 5.2.4.4 to 5.2.6, Node.js from 15.14.0 to 22.17.1, and updated related dependencies in Dockerfile, .ruby-version, .node-version, and Gemfile. This ensures compatibility with newer libraries and improves security and performance. [1] [2] [3] [4] [5] [6]

• Updated GitHub Actions workflow to use the new Ruby and Node.js versions and switched to custom build/push actions (@ppan branch) for Docker images. [1] [2] [3]

• Added a comprehensive .env-example file with new environment variables for database, throttling, Omniauth, and feature toggles, making local setup and configuration more transparent and robust.

Omniauth FranceConnect Enhancements:

• Improved Omniauth FranceConnect integration by adding support for button_hover_path and post_logout_redirect_uri in both configuration and UI, allowing for custom hover images and better logout handling. [1] [2] [3] [4] [5]

• Updated Omniauth provider setup to use issuer instead of site and post_logout_redirect_uri instead of end_session_endpoint for better standards compliance and flexibility. [1] [2]

• UI improvements for social login buttons, including hover state support for custom images and related SCSS changes to enhance the login/signup user experience. [1] [2] F4e40f55L4e40f55L223R223, [3]

Other Notable Improvements:

• Added support for enabling letter_opener in production via an environment variable, allowing for easier email debugging in non-development environments. [1] [2] [3]

• Added new initializers and required files for extending OpenID Connect support.

• Updated localization files (en.yml, fr.yml) to support new Omniauth configuration options and improved user-facing explanations. [1] [2] [3]

These changes collectively modernize the stack, improve configuration management, and enhance the user experience for authentication via FranceConnect.