Fixes#41.
MySQL columns now decode by their declared type instead of a blind try_get chain,
so every non-string type (integers, DECIMAL, BIT, YEAR, DATE/TIME/DATETIME/TIMESTAMP)
renders its value instead of NULL. MySQL restore runs in-process over the sqlx driver
(no bundled MariaDB client, so MySQL 8 caching_sha2_password works) and the Clean toggle
is implemented. .sql files can be opened with Gridline from the OS file manager.
Verified: cargo test --lib 442 passed / 0 failed; bun run test 133 files / 1151 tests
exit 0; tsc clean; both live MySQL 8 integration tests pass with the bundled CLI hidden.
