[plan] Create validation helpers and boundary tests

[github-actions]

Objective

Create reusable validation helper functions and comprehensive boundary value tests for the 4 newly validated constraint fields.

Context

After fixing the 4 specific constraint validations, we need:

1. Reusable validation helpers to prevent code duplication
2. Comprehensive tests to ensure boundary conditions are properly handled
3. Documentation of validation patterns for future development

Approach

Part 1: Validation Helpers

Create validation utility functions in appropriate location (e.g., pkg/workflow/validation.go or new pkg/workflow/validation_helpers.go):

func validateIntRange(value, min, max int, fieldName string) error {
    if value < min || value > max {
        return fmt.Errorf("%s must be between %d and %d, got %d",
                          fieldName, min, max, value)
    }
    return nil
}

Part 2: Unit Tests

Create or update test files to cover boundary conditions for each field:

• pkg/workflow/gateway_test.go - Port validation tests
• pkg/workflow/repo_memory_test.go - File size/count/retention tests

Test cases for each field:

• Minimum valid value (should pass)
• Maximum valid value (should pass)
• Below minimum (should fail with clear error)
• Above maximum (should fail with clear error)
• Zero value (should fail if minimum > 0)
• Negative value (should fail)

Files to Create/Modify

• Create or update: pkg/workflow/validation_helpers.go - Reusable validation functions
• Update: pkg/workflow/gateway_test.go - Port boundary tests
• Update: pkg/workflow/repo_memory_test.go - File size/count/retention boundary tests

Acceptance Criteria

• Validation helper function created and documented
• Port field has 6+ test cases (min, max, below, above, zero, negative)
• Max-file-size field has 6+ test cases
• Max-file-count field has 6+ test cases
• Retention-days field has 6+ test cases
• All tests pass with make test-unit
• Code coverage maintained or improved
  Related to [plan] Fix missing constraint validations in parser/compiler #7524

AI generated by Plan Command for discussion #7454