feat: add HTTP and WebSocket remote agent support to workflow tool

[AK-Soni-AWS]

• Add _execute_remote_task() method for HTTP remote agent invocation
• Add _execute_websocket_task() method for WebSocket streaming agents
• Support both standard workflow format and AgentCore gateway format
• Add OAuth authentication via auth_token parameter
• Add AgentCore session management via session_id parameter
• Update execute_task() to route remote agents appropriately
• Add comprehensive test coverage for remote agent execution
• Add complete example in tmp/example/ with AgentCore deployment
• Update documentation with remote agent usage patterns

Description

This PR extends the workflow orchestration tool to support distributed task execution via remote agent URLs. This enables workflows to delegate tasks to specialized agents running on remote services without requiring local dependencies.

Related Issues

Fixes #403

Documentation PR

Type of Change

Other (please describe): New feature to existing tool (non-breaking change which adds functionality)

Testing

Test Results

✅ All 38 tests passed (100% success rate)

• 6 new remote agent tests
• 32 existing workflow tests (backward compatibility confirmed)
• Standalone test script

Test Coverage

• Remote agent URL detection
• HTTP POST communication
• Bearer token authentication
• Timeout handling
• HTTP error handling (4xx, 5xx)
• Connection error handling
• Context passing to remote agents
• Hybrid workflows (local + remote)
• Task routing logic
• Backward compatibility

Backward Compatibility

✅ Fully backward compatible

• All existing workflow tests pass without modification

• No breaking changes to API

• Existing workflows work unchanged

• Local agent execution unchanged

• New parameters are optional

• [ X] I ran hatch run prepare

Checklist

• [ X] I have read the CONTRIBUTING document
• [ X] I have added any necessary tests that prove my fix is effective or my feature works
• [ X] I have updated the documentation accordingly
• [ X] I have added an appropriate example to the documentation to outline the feature
• [ X] My changes generate no new warnings
• [ X] Any dependent changes have been merged and published

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