Add Testing Infrastructure for NEST

[destroyersrt]

Add Testing Infrastructure for NEST

Description

Implement comprehensive testing infrastructure with unit, integration, and E2E tests. Given NEST's distributed multi-agent nature with protocol communication, registry integration, and cloud deployments, a layered testing approach is needed.

Recommend Testing Strategy

1. Unit Tests

• Protocol adapters (A2A, SLIM message formatting)
• Protocol router logic
• AgentFacts parsing
• @mention extraction and routing
• Framework/LLM provider adapters

2. Integration Tests

• Protocol communication flows (mock external agents)
• Registry client interactions (mock NANDA Index)
• Payment flow (mock blockchain facilitator)
• Framework-to-protocol bridge

3. E2E Tests

• Multi-agent scenarios with real protocol communication
• Agent discovery via local registry
• Cross-framework agent collaboration

4. Contract Tests

• A2A spec compliance (AgentCard format, JSON-RPC 2.0)
• SLIM protocol compliance
• x402 payment headers

Acceptance Criteria

• pytest configured with coverage reporting
• Unit tests for all protocol adapters (>80% coverage)
• Integration tests with mocked external dependencies
• E2E test suite using Docker Compose with 2-3 test agents
• Test fixtures for common scenarios (agent configs, mock responses)
• Mock NANDA Index for integration tests
• E2E tests cover: agent discovery, @mention routing
• Documentation for running tests locally and adding new tests