C++ Application Enhancement and Bug Fixing

I have an existing C++ desktop application that is already developed and working. I need an experienced C++ developer to enhance and fix several parts of the project.

Scope of Work:

CAPTCHA Integration (No Third-Party Services)
I need to add a CAPTCHA system into my application.

It must NOT use any third-party CAPTCHA solving services or paid APIs (no 2Captcha, AntiCaptcha, etc.).

The solution should work locally.

Preferred approach: machine learning-based CAPTCHA recognition (for example using OpenCV or another suitable C++-compatible method).

It must be optimized for speed and low delay.

Clean and maintainable implementation is required.

Modify / Improve Existing Scripts

Update and adjust some existing logic inside the C++ application.

Improve performance and stability if possible.

Ensure the code remains organized and readable.

Fix Visual Studio Errors

Currently, there are build/configuration errors on my PC.

The developer must identify and fix these issues.

Ensure the project builds and runs properly in Visual Studio.

Provide clear instructions on how to build and run the project after fixing.

Requirements:

Strong experience with C++ (modern standards preferred).

Experience integrating image processing or machine learning in C++.

Strong debugging skills in Visual Studio.

Ability to communicate clearly, as I do not have a programming background.

Deliverables:

Fully working updated C++ application.

Integrated CAPTCHA system (no third-party services).

Fixed Visual Studio project configuration.

Clear instructions for building and running the project.

Clean and organized source code.

Please explain your approach and estimated timeline when bidding.