phpMyAdmin login was broken because phpmyadmin_install.sh never wired
the private phpMyAdmin copy into the web server: no Apache Alias was
registered via DirectAdmin CustomBuild, so the SSO redirect target was
unreachable. Add configure_apache_alias()/apply_apache_alias() (Alias +
Directory blocks, ./build rewrite_confs, httpd reload), detect the real
Apache group instead of hardcoding diradmin:diradmin, stop silently
swallowing chown/chmod failures, and verify an optional SHA256 for the
downloaded phpMyAdmin tarball. Extend phpmyadmin_health_check.sh to
detect a missing/incorrect Apache alias and to probe HTTP reachability.
Security hardening: scope temporary phpMyAdmin SSO MySQL roles to
127.0.0.1 instead of '%', tighten SSO ticket file permissions to 0640
(they contain a plaintext MySQL password), and log MySQL connection
failures for diagnosis instead of swallowing them silently.
Bump version to 1.2.12 and rebuild the release archive.