✨ Adds MariaDB image with direct LDAP PAM authentication

- Introduced a new Containerfile to build a MariaDB image with direct LDAP PAM support.
- Implemented a custom PAM module (`pam_ldap_direct.so`) built from the PADL source to avoid dependencies on `libpam-ldap` and `nslcd`.
- Updated the entrypoint script to dynamically generate the PAM configuration file (`/etc/pam_ldap.conf`) based on environment variables.
- Added a README.md to document the image usage, configuration, and build process.
- Created a test suite to validate the image build and entrypoint behavior, ensuring proper handling of environment variables and configuration generation.
- Configured health checks and ensured the stock MariaDB entrypoint and lifecycle are preserved.

database/compose.yaml

@@ -33,12 +33,12 @@ services:
         - PGPOOL_VERSION=${PGPOOL_VERSION:-4.7.2}
 
   mariadb:
-    image: containers.kritikos.io/system/mariadb-extended:${MARIADB_VERSION:-12}
+    image: containers.kritikos.io/system/mariadb-extended:${MARIADB_VERSION:-13.0.2}
     build:
       context: mariadb
       dockerfile: Containerfile
       args:
-        - MARIADB_VERSION=${MARIADB_VERSION:-12}
+        - MARIADB_VERSION=${MARIADB_VERSION:-13.0.2}
 
   ldap2mariadb:
     container_name: ldap2mariadb