feat: Add stock rice visualization Demo

[DennisYu07]

Overview

This PR delivers a fully functional, personalized stock investment experience by leveraging the synergy of Qwen for intelligent insights and Supabase as the real-time, secure backend infrastructure.

All user-facing features—from authentication to portfolio analytics—are built on Supabase’s BaaS while Qwen enables contextual understanding and future-ready AI capabilities (e.g., natural language queries, market summaries).

Key Features

User Authentication via Supabase Auth

• Secure email/password and OAuth sign-up/login using Supabase GoTrue
• Row-Level Security (RLS) policies ensure users only access their own data

Personalized Dashboard & Real-Time Visualization

• Built on Supabase subscriptions for live stock price updates

Watchlist Management

• Add/remove stocks stored in watchlists table
• Real-time sync data

Simulated Trading & Portfolio Tracking

• Virtual trading engine with balance and order history stored in Supabase
• Portfolio positions automatically calculated

[pomelo-nwu]

@DennisYu07 Thank you for your contribution! However, this demo doesn't seem to be related to the Qwen-Code SDK, skills, or commands demonstration topics, does it?