Addresses #44 (closed after the v0.8.3 release builds are green).
Three independent defects in one shared tool-resolution path: bundled tools were
looked up at the wrong path (so bundled fallback never worked, for PostgreSQL
too), macOS GUI apps inherit launchd's minimal PATH, and only mariadb-dump/mariadb
were probed — never mysqldump/mysql, which is what brew install mysql-client
installs. Both engines now resolve through one headless, cached, timed resolver,
plus a non-blocking client/server version warning.
Also fixes passing MySQL-only CLI options to the bundled MariaDB client, and
carries the tool-page UI polish and the requested #40 icon revert.
adrianbonpin