Hitless handshake

[elena-kolevska]

Pull Request check-list

Please make sure to review and check all of these items:

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)? N/A
• Is there an example added to the examples folder (if applicable)? N/A

NOTE: these things are not required to open a PR and can be done
afterwards / while the PR is open.

Description of change

• Adds handshake for hitless upgrades
• Updates the server maintenance message format to include the sequence ID

[Copilot]

Pull Request Overview

This PR implements hitless handshake functionality for Redis maintenance events by adding a handshake process and updating message formats to include sequence IDs. The changes enable clients to negotiate maintenance notification preferences with the server during connection establishment.

• Adds endpoint type detection and validation for CLIENT MAINT_NOTIFICATIONS command
• Updates server maintenance message format to include sequence ID as the first parameter
• Changes default maintenance events configuration from disabled to enabled

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
redis/maintenance_events.py	Adds EndpointType class and endpoint detection logic to MaintenanceEventsConfig for handshake negotiation
redis/connection.py	Implements CLIENT MAINT_NOTIFICATIONS handshake during connection establishment and adds IP resolution method
redis/_parsers/base.py	Updates message parsing to handle new format with sequence ID as first parameter
tests/test_maintenance_events.py	Adds comprehensive tests for endpoint type detection and validation
tests/test_maintenance_events_handling.py	Updates mock server responses to match new message format with sequence ID

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[Copilot]

The broad exception handling catches all exceptions during the handshake process. Consider being more specific about which exceptions to handle and potentially re-raise authentication or connection errors that shouldn't be silently ignored.

Suggested change

	except (AuthenticationError, ConnectionError) as e:
	# Re-raise critical connection/authentication errors
	raise
	except ResponseError as e:
	# Log warning but don't fail the connection for expected server response errors
	import logging
	logger = logging.getLogger(__name__)
	logger.warning(f"Failed to enable maintenance notifications: {e}")