Add SearxNG support to enhance search engine flexibility

[Luojz]

Add SearxNG support to enhance search engine flexibility

Features

• Added SearxNG as an alternative search engine option
• Implemented configurable search engine selection in config.toml
• Maintained compatibility with existing Google search functionality
• Added support for custom SearxNG instance configuration
• Preserved the same interface for all search engines

Feature Docs

Configuration example in config.toml:

[search_engine]
type = "searxng"  # Supported types: google, searxng
base_url = "http://127.0.0.1:8080"  # SearxNG service address

Users can easily switch between search engines by modifying the config file:

1. Use Google search (default): type = "google"
2. Use SearxNG: type = "searxng" with custom base_url
3. Extensible design for adding more search engines in future

Influence

• Functionality:
  • Free and open-source alternative to Google search
  • More search options for different scenarios
  • Easy to switch between search engines
• Extensibility:
  • Modular design for adding new search engines
  • Configuration-based engine selection
  • No code changes needed to switch engines

Result

Example usage remains the same while supporting multiple engines:

# Returns same format regardless of engine choice
results = await search_tool.execute(query="test", num_results=10)
# Returns: ["url1", "url2", ...]

Other

• Zero breaking changes to existing functionality
• Added documentation for SearxNG configuration
• Prepared foundation for future search engine integrations
• All search engines follow the same interface pattern

[ghmole]

very useful feature

[mannaandpoem]

Please update code and resolve conflict