Without UPLOAD_LIMIT the phpMyAdmin image keeps PHP's default 2M
post_max_size/upload_max_filesize, so importing any SQL file larger
than 2MB fails with 'POST Content-Length exceeds the limit of
2097152 bytes' followed by a session_start error page.
- Add UPLOAD_LIMIT (512M) and MAX_EXECUTION_TIME (600) env vars,
configurable from the template env
- Wire the previously unused MYSQL_DATABASE env var into the compose
file, replacing the hardcoded 'tu_base_de_datos' placeholder, and
default it to 'phpmyadmin' instead of the system 'mysql' schema
Closes#236
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
