Add Custom Logger and types for better data handling, type checking a…

[Einswilli]

✨ Pull Request – Strong Typing & Basic Logging Module

Hi team 👋,

This PR introduces two key improvements aimed at increasing the quality, maintainability, and robustness of the SDK:

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1. 🧾 Added types.py for Strong Typing

• Introduces explicit types for more fine-grained control over data structures.
• Improves type safety and consistency, making the codebase easier to navigate and work with (especially for IDEs and tools like MyPy).
• Lays a solid foundation for future enhancements and scalability.

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2. 🪵 Introduced a Basic Logging Module

• Adds a simple but extensible logging system, including a configuration model (LoggingConfig) and a dedicated logger class (KKiaPayLogger).
• Enables better tracking of key events such as payments, refunds, API calls, and webhook receptions.
• Prepared to support more complex or asynchronous environments in the future.

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🛠️ Why This Is Split

Initially, I intended to include a larger refactor (better flexibility, extensibility, robustness, and structural consistency) in this single PR.
However, to make review, testing, and discussion easier, I decided to split it into smaller, focused pull requests.

Upcoming PRs will include:

• A more modular SDK structure.
• Clean integration with the httpx client.
• Improved error handling and typed API responses.
• More flexible configuration and extension mechanisms.

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Looking forward to your feedback, and thank you! 🙏

— Einswilli