demo: A2A interop test with Google ADK-Go agent

Summary

Compile and run a Google ADK-Go example agent alongside DocsClaw to validate A2A interoperability between the two runtimes. This demonstrates that DocsClaw works seamlessly in heterogeneous multi-agent environments.

Motivation

Customer questions arise about why DocsClaw isn't built on Google ADK. The strongest counter-argument is model independence (ADK is Gemini-only), but we should also show concrete A2A interop: DocsClaw can delegate to ADK agents and vice versa.

Tasks

• Clone https://github.com/google/adk-go and pick a simple example agent
• Compile and run the ADK agent on one port
• Run DocsClaw on another port
• Test bidirectional A2A delegation using a2a CLI
• Document the setup in docs/ as an interop guide

Context

• DocsClaw and ADK-Go both use a2a-go v2 for the A2A protocol
• ADK-Go ships only Gemini provider; DocsClaw supports Anthropic + OpenAI
• This validates DocsClaw's positioning as a model-independent runtime that interoperates with framework-specific agents

Start by cloning the Google ADK-Go repository and selecting a simple example agent, then run it and DocsClaw on separate ports. Use the a2a CLI to test delegation in both directions, and document the working setup and commands in docs/ as the interop guide.