osaring sizer

This is a Ring Size Measurement Android app. Key features include:

1. Ring Size Measurement (Core Feature)
- Ring Mode: Place a ring on screen and adjust the circle to match; uses screen calibration for mm-level
accuracy
- Finger Mode: Place your finger on screen to measure; supports left/right hand switching with finger
visualization and directional arrow guides
- Precise diameter adjustment via slider, automatic circumference calculation, mapped to US ring sizes (4–16)
- Smart recommendation: auto-suggests sizing up when measurement is near a size boundary

2. Measurement Results & History
- Dialog showing measurement results (size label, diameter, circumference) with wearing advice
- Logged-in users can save measurements and view history

3. Ruler Tool
- Full-screen vertical ruler with mm/cm unit switching, calibrated based on screen DPI

4. Articles
- Browse ring-related knowledge articles (list + detail view)

5. Customer Service Chat
- Real-time WebSocket-based chat with text and image support, unread message badge

6. User System
- Sign up, login, and forgot password flows

7. User Guidance
- Onboarding screen for first launch, video tutorials for ring and finger measurement

8. Others
- Feedback submission, contact us, privacy policy, terms of use, settings page