Definition
/**
* Create a condition builder for fluent condition composition.
*
* This builder allows incremental condition building with a fluent API:
*
* ```php
* $builder = conditions();
*
* if ($hasFilter) {
* $builder = $builder->and(eq(col('status'), literal('active')));
* }
*
* if (!$builder->isEmpty()) {
* $query = select()->from(table('users'))->where($builder);
* }
* ```
*/
conditions() : ConditionBuilder