Fix record: mixed-* findings in Connection/Pdo/Connection/Ddl decorators stem from untyped upstream array boundaries

[tyrsson]

Context

Part of #60.

Data

Multiple mixed-argument/mixed-assignment/mixed-array-assignment/less-specific-argument findings trace to untyped array boundaries in upstream php-db/phpdb:

• AbstractConnection::$connectionParameters (protected array $connectionParameters = [];, no shape) — affects src/Connection.php and src/Pdo/Connection.php.
• ColumnInterface::getOptions(): array and matching CreateTable::getOptions() / AlterTable::getOptions() (untyped array return) — affects src/Sql/Ddl/AlterTableDecorator.php and src/Sql/Ddl/CreateTableDecorator.php.
• AlterTable's 7 untyped array properties ($addColumns, $addConstraints, $changeColumns, $dropColumns, $dropConstraints, $dropIndexes, $options) and CreateTable's 4 ($columns, $constraints, $options, $specifications) — all declared protected array $x = []; with no shape docblock. Concretely, this is why foreach ($this->changeColumns as $name => $column) in AlterTableDecorator::processChangeColumns() resolves $name to generic array-key rather than string, producing a less-specific-argument finding at PlatformInterface::quoteIdentifier($name) — left unsuppressed and uncast intentionally, so the baseline entry can be dropped cleanly once the upstream shape lands, without a workaround cast to remove.

Tracked upstream at php-db/phpdb#169.

These findings will be captured in a mago baseline rather than fixed or suppressed inline, pending the upstream fix.