Add Intelica as x402 merchant example for competitive intelligence use case

## Summary

AgentKit enables agents to make x402 payments. Adding [Intelica](https://api.intelica.dev) as an example merchant would show a **competitive intelligence** use case — agents that evaluate markets before making decisions.

## The use case

An AgentKit-powered agent that:
1. Receives a task: "Should I enter the SEA fintech market?"
2. Calls Intelica via x402 (`POST https://api.intelica.dev/intel`)
3. AgentKit pays $0.05 USDC automatically
4. Agent receives: `action: avoid`, `imi: 0.82`, `rationale`, `competitors`, `execution_plan`
5. Agent takes action based on the decision

## Code example

```python
from coinbase_agentkit import AgentKit, AgentKitConfig
from coinbase_agentkit_langchain import get_langchain_tools
import requests

# AgentKit handles wallet and x402 payment
kit = AgentKit(AgentKitConfig(cdp_api_key_name="...", cdp_api_key_private_key="..."))

# Custom tool that calls Intelica
def analyze_market(query: str) -> dict:
response = requests.post(
"https://api.intelica.dev/intel",
json={"text": query, "mode": "competitive"},
# AgentKit intercepts 402 and pays automatically
)
return response.json()["decision_recommendation"]
```

## x402 compliance
- x402Version: 2 · PAYMENT-REQUIRED header · eip155:8453 + Solana
- Agentic Market: all checks pass
- Graph: 3,600+ companies

Docs: https://api.intelica.dev/llms-full.txt