Added simple example for imcompatible allocators

[vikashsiwach]

Summary

This PR adds a minimal example demonstrating the "incompatible_allocators" problem between Rust and C++.
The example shows a case where memory is allocated in Rust and ownership is transferred to C++, which then attempts to deallocate it using a different allocator. This results in undefined behavior.

What this example demonstrates

• Allocation of memory in Rust (using vec)
• Passing a raw pointer and length across the FFI boundary
• Incorrect deallocation in C++ using free()
• Why allocator compatibility is required for soundness

Why this is useful

This example highlights that allocator compatibility is equally important.

Notes

• The example may appear to work on some systems, but it is still undefined behavior.
• This is intentionally incorrect code to demonstrate the problem.

Future work (optional)

This example could be extended to include:

• A correct approach where Rust deallocates the memory
• Variants using Box or other allocation patterns

[teor2345]

Hi, thanks for this example! I've already seen your first PR in #24, let's focus on one PR at a time.

Once that PR has finished, we can decide what to do with this one. I'll mark this PR as draft until then.

[vikashsiwach]

I have updated the project structure with different folder for incompatible allocators example. I have added run.sh file for CI. It is passing now all checks. @teor2345 I request you to review the PR and give your feedback.

[teor2345]

Hi, thanks for this example! I've already seen your first PR in #24, let's focus on one PR at a time.

Once that PR has finished, we can decide what to do with this one. I'll mark this PR as draft until then.

Sorry, we're focusing on one PR per person for now.