docs: Add SDK usage examples for Python client

[Levaj2000]

Summary

The Python SDK in sdk/python/ needs usage examples showing common workflows:

• Registering a new agent
• Creating and attaching a policy
• Querying audit logs programmatically
• Exporting forensic reports

What to do

1. Create an sdk/python/examples/ directory
2. Add 2-3 standalone Python scripts demonstrating real workflows
3. Each script should include inline comments explaining what's happening
4. Update sdk/python/README.md (create if needed) linking to the examples

Context

The API docs are live at ai-identity-api.onrender.com/docs — use these as reference for available endpoints.

Acceptance criteria

• At least 2 example scripts in sdk/python/examples/
• Scripts are runnable (with a valid API key)
• README links to examples