[Analysis] Statement.php: mixed-assignment in bindParametersFromContainer() stems from ParameterContainer::getNamedArray()

[tyrsson]

Context

Part of #60.

Data

mago analyze flags mixed-assignment on $value in bindParametersFromContainer()'s foreach ($parameters as $name => &$value) loop. $parameters comes from ParameterContainer::getNamedArray(): array (upstream php-db/phpdb, docblock @return array<string|int, mixed>). This is not an untyped-boundary bug: bind parameter values are legitimately heterogeneous scalars (int/string/float/null) by design, so mixed is an accurate description of the value, not a gap to close.

These findings will be captured in a mago baseline rather than fixed or suppressed inline.