[#33] Move config from php fpm script to wp-config

Description

Move and add dynamic configuration improvements to our WordPress container setup:

• Dynamic Database & Site Settings:
  • Database credentials and table prefix are loaded from environment variables from wp-config.php.
  • Site URL constants (e.g. WP_HOME, WP_SITEURL) are defined based on the APPLICATION_NAME environment variable and loaded from wp-config.php.
  • Filters override site options like blogname and admin_email to reflect environment values without unnecessary database writes.
• Dynamic OpenID Connect Settings:
  • A must-use plugin (openid-settings.php) has been added to automatically update the openid_connect_generic_settings option during the init hook.
  • The plugin merges existing settings with new values derived from environment variables, ensuring that the OpenID Connect plugin always uses current configuration data without manual intervention.
• Dynamic Authentication Keys & Salts:
  • Instead of hardcoding security keys, the configuration now fetches random salted keys from the WordPress.org secret-key API and defines them dynamically.

Testing

1. Run make build & make up.

2. Checked if openid_connect_generic_settings existed:

   

3. Blog Options are correctly populated:

   

4. Security keys are salted and correctly populated

   

5. Site correctly loads !