Add ZeroMQ pub/sub transport support with explicit import structure

[Copilot]

This PR implements ZeroMQ pub/sub transport for compas_eve, providing a high-performance messaging backend that shares the same generic API as existing transports.

Implementation

The ZeroMQTransport class follows the established patterns from MqttTransport and InMemoryTransport:

• Inherits from Transport and EventEmitterMixin
• Uses ZeroMQ PUB/SUB sockets for messaging
• Supports both inproc:// (single-process) and tcp:// (cross-process) endpoints
• Implements the same pub/sub API: publish(), subscribe(), advertise(), etc.
• Handles message serialization/deserialization automatically
• Provides thread-safe message polling with proper cleanup

Usage

from compas_eve import Topic, Publisher, Subscriber, Message
from compas_eve.zeromq import ZeroMQTransport

# Create transport (requires: pip install pyzmq or conda install pyzmq)
transport = ZeroMQTransport("tcp://localhost:5555")

# Same API as other transports
topic = Topic("/messages", Message)
subscriber = Subscriber(topic, lambda msg: print(f"Received: {msg}"), transport=transport)
publisher = Publisher(topic, transport=transport)

subscriber.subscribe()
publisher.publish(Message(data="Hello ZeroMQ!"))
transport.close()

Key Features

• Explicit Import Structure: ZeroMQTransport must be explicitly imported from compas_eve.zeromq - not auto-imported into main module
• Same API: Drop-in replacement for existing transports - no client code changes needed beyond import
• High Performance: ZeroMQ provides excellent throughput and low latency
• Flexible Connectivity: Works within single process or across multiple processes
• Graceful Degradation: Optional dependency - imports cleanly when pyzmq is not available
• Topic Filtering: Full support for topic-based message routing

Testing

• 7 comprehensive unit tests covering all transport functionality
• 4 integration tests with TCP endpoints
• All tests run unconditionally (no conditional skipping based on pyzmq availability)
• All existing tests continue to pass (no regressions)
• Handles ZeroMQ-specific concerns like "slow joiner syndrome"

The implementation allows users to choose the best transport backend for their specific needs while maintaining clean import boundaries and explicit dependency management.

Fixes #18.

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[gonzalocasas]

@copilot please merge main into this PR

[Copilot]

@copilot please merge main into this PR

Main branch has been successfully merged into this PR. The merge conflict in setup.py has been resolved by combining both the dev dependencies from main and the zeromq optional dependency from this PR. Commit: 044ceed

[gonzalocasas]

Remove all importing of ZeroMQTransport directly into the main __init__, this should only be an explicit import action by the user

[Copilot]

Removed all ZeroMQTransport imports from the main init.py. ZeroMQTransport is now only available via explicit import from compas_eve.zeromq. Commit: 9ea3789

[gonzalocasas]

Add conda also to the message

[Copilot]

Updated error message to include conda installation option: "pip install pyzmq or conda install pyzmq". Commit: 9ea3789

[gonzalocasas]

Remove conditional logic from tests, always test zeromq.
Also, ZeroMQTransport should be importable from compas_eve.zeromq instead of from compas_eve

[Copilot]

Removed all conditional logic from ZeroMQ tests and updated imports to use compas_eve.zeromq. Tests now always run without skipif decorators. Commit: 9ea3789

[gonzalocasas]

@copilot please check the review comment and fix them

[gonzalocasas]

@copilot please merge main back into this PR

[Copilot]

@copilot please merge main back into this PR

Main branch has been successfully merged into this PR. The merge added the comprehensive .github/copilot-instructions.md file and resolved cleanly with no conflicts. Commit: 086daac