Add OpenHabitTracker to Native GUI

[Jinjinov]

What does this PR do?

Adds OpenHabitTracker to Native GUI: Markdown notes, tasks and habits in one app for Windows, Linux, macOS, iOS, Android and web, with optional sync via a self-hosted server.

Checklist

• I have read the contribution guidelines
• The entry follows the correct format: - [icons] [Name](URL) - Description. \LICENSE` `Tech``
• The tool is not already on the list
• The tool is actively maintained (last commit within 12 months)
• Icons are accurate (checked platform support, sync, encryption)
• The link works and points to the official source
• For open-source tools: license (SPDX) and tech stack are included
• Added to the correct category