Refactor middleware for better readability

**Description**
Currently validation lacks proper pagination support.

**Proposed solution**
Add configurable pagination with sensible defaults.

**Priority**: Low/Medium

Start by locating the middleware validation entry point and reading how validation currently handles collections or result limits. Define the expected configurable pagination options and sensible defaults from the existing behavior, then verify that validation supports paginated results without breaking current callers. Add or update focused validation tests if the project has them.

Written by the indexing model from the issue text.