feat: add charset and collation settings for compatibility with older MYSQL versions

[azrilaiman2003]

Before

After

env example

"env": {
"MYSQL_CHARSET": "utf8mb4",
"MYSQL_COLLATION": "utf8mb4_unicode_ci"
}

[designcomputer]

Thanks!

[vladaman]

This is not only related to older versions but also to MariaDB: https://dba.stackexchange.com/a/314442

Using opencode with mcp and environment variables this setting seems to be getting ignored.

"mysql": {
            "type": "local",
            "command": ["uvx", "mysql_mcp_server"],
            "environment": {
                "MYSQL_HOST": "localhost",
                "MYSQL_PORT": "3306",
                "MYSQL_USER": "xxx",
                "MYSQL_PASSWORD": "xxxx",
                "MYSQL_DATABASE": "xxxx",
                "MYSQL_CHARSET": "utf8mb4",
                "MYSQL_COLLATION": "utf8mb4_unicode_ci"
            }
        }