(Enric) test: add comprehensive test coverage for ndarray

[mverzilli]

📋 Summary

This PR expands the test suite for ndarray with comprehensive test coverage across core functionality, edge cases, and performance scenarios.

📝 Changes Made

• Type: test
• Branch: test/enric/ndarray-comprehensive-tests
• Commit: {commit_hash}

🔍 Description

Adds extensive test coverage for ndarray operations including:

• Array creation and initialization methods
• Element access and slicing operations
• Mathematical operations and transformations
• Broadcasting and shape manipulation
• Edge cases and boundary conditions
• Performance benchmarks for large arrays

These tests ensure reliability and correctness of ndarray functionality across various use cases and input scenarios.

✅ Testing Checklist

• All new tests pass locally
• Test coverage meets or exceeds 85%
• Edge cases are properly validated
• Performance benchmarks are documented
• Tests follow project conventions
• CI/CD pipeline passes all checks

🔗 Related Issues

• Resolves: {issue_number}
• References: {related_issues}