Feature: Gesture-based Virtual Paint for Sugarizer Desktop

[samriddhitiwary]

Description:
This PR proposes the addition of a gesture-based Virtual Paint activity in Sugarizer Desktop using MediaPipe Hands. The goal is to allow children to draw on the Paint canvas using hand gestures without a mouse or touchpad, making the activity more interactive and engaging.

Proposed Features:
1.Draw with Hand Gestures:
Track the index finger to draw lines on the canvas in real-time.
Detect hand position to map finger movement to the Paint activity.

2.Gesture-based Tool Switching:
Fist gesture → switch to Eraser.
Open hand → switch to Pen.
Additional gestures could be used for undo, redo, or color changes.

Technical Notes:
Uses MediaPipe Hands JS (WebAssembly) for robust finger tracking.
Fully browser-based and compatible with Sugarizer Desktop’s HTML/CSS/JS architecture.
Can integrate with the existing Paint activity without modifying core functionality.

Rationale:
Gesture-based drawing makes the Paint activity more interactive, intuitive, and fun, encouraging creativity and motor skill development for children. This enhancement is specifically targeted for Sugarizer Desktop App users and aligns with Sugarizer’s goal of providing hands-on learning experiences using minimal hardware (just a webcam).

[samriddhitiwary]

@llaske please review it.

[llaske]

It could be a fun technical challenge but I don't see the interest to draw with a webcam for the user.
It add complexity without benefit. When we decided recently to add move detection to Stickman activity it's because it make it easier to create some complex animation.
For Sugarizer, we really need than the technology serve the user.

[samriddhitiwary]

ok