feat: add free-web-search-ultimate integration — zero-cost web search for CrewAI agents

[wd041216-bit]

Summary

Adds an integration example for free-web-search-ultimate (v13.0.0) — a zero-cost, API-key-free web search tool for CrewAI agents.

Why this is valuable for CrewAI users:

• Agents need real-time web search to complete research tasks
• Most search tools (Tavily, SerpAPI, Exa) require paid API keys
• free-web-search-ultimate works out of the box with zero configuration
• Supports DuckDuckGo, Bing, Google, Brave, Yahoo + news/images/videos

Files added:

• integrations/free_web_search/README.md — setup guide and usage examples
• integrations/free_web_search/main.py — complete CrewAI agent example

Install: pip install free-web-search-ultimate==13.0.0
PyPI: https://pypi.org/project/free-web-search-ultimate/
GitHub: https://github.com/wd041216-bit/free-web-search-ultimate

[wd041216-bit]

🔄 Updated to cross-validated-search v14.0.0

This PR has been updated to reflect the renaming and rebranding of the package:

Changes:

• Package renamed: free-web-search-ultimate → cross-validated-search
• New focus: Cross-validation for hallucination prevention
• Version: v13.0.0 → v14.0.0
• CLI command: search-web → cross-validate

Key Features:

• ✅ Confidence scoring: Every fact gets a confidence level (✅ Verified / 🟢 Likely True / 🟡 Uncertain / 🔴 Likely False)
• ✅ Cross-validation: Facts verified against multiple independent sources
• ✅ Anti-hallucination: Prevents LLM from fabricating facts
• ✅ Zero-cost, privacy-first: No API keys required