feat: Add DashScope provider support for Qwen3 models

[byronwang2005]

📝 Pull Request Template

1. Related Issue

Closes #429

2. Type of Change (select one)

Type of Change: New Feature

3. Description

Changes Made:

This PR adds complete support for DashScope (Alibaba Cloud Qwen3 models) provider integration, including both backend and frontend components.

Backend Changes:

• Created DashScopeProvider class in python/valuecell/adapters/models/factory.py that implements OpenAI-compatible API interface
• Registered DashScope provider in ModelFactory._providers registry
• Added dashscope.yaml configuration file with Qwen3 model definitions (qwen-max, qwen-plus, qwen-turbo, qwen-7b-chat, qwen-14b-chat)
• Configured embedding model support (text-embedding-v2, text-embedding-v1)
• Updated config.yaml to register DashScope provider
• Added API key URL mapping in models.py router pointing to Alibaba Cloud Bailian console
• Updated provider exports in __init__.py

Frontend Changes:

• Added DashScope icon mapping in constants/icons.ts
• Added DashScope icon import in assets/png/index.ts
• Icon file placed at frontend/src/assets/png/model-providers/dashscope.png

Configuration Updates:

• Updated .env.example with DASHSCOPE_API_KEY environment variable
• Updated CONFIGURATION_GUIDE.md with DashScope setup instructions and examples

Why This Change is Necessary:

DashScope provides access to Qwen3 series models which are optimized for Chinese language tasks and offer competitive performance. Adding DashScope support:

• Expands model provider options for users, especially those in China
• Provides access to Qwen3 models (qwen-max, qwen-plus, qwen-turbo) with strong Chinese language capabilities
• Maintains consistency with existing provider architecture (OpenAI-compatible API)
• Enables users to leverage Alibaba Cloud's AI services within ValueCell

API Endpoints:

• Base URL: https://dashscope.aliyuncs.com/compatible-mode/v1
• API Key Console: https://bailian.console.aliyun.com/#/home

4. Testing

• I have tested this locally.

  • Verified DashScope provider registration in ModelFactory
  • Confirmed configuration files load correctly
  • Tested API endpoint returns provider information
  • Verified frontend displays DashScope in provider list

• I have updated or added relevant tests.

5. Checklist

• I have read the Code of Conduct

• I have followed the Contributing Guidelines

• My changes follow the project's coding style

  • Followed existing provider implementation pattern
  • Used consistent naming conventions
  • Added appropriate comments and documentation
  • No linter errors introduced

[byronwang2005]

Some of my invocation methods are still in compatibility mode—give me a moment to update them.

[hazeone]

LGTM