RUBY-3241 URI option for monitoring type

[comandeo-mongo]

Implements the serverMonitoringMode URI option per the URI options spec. Accepted values are stream, poll, or auto (default).

• When set to poll, the driver never creates a push monitor, even if the server supports streaming (4.4+).
• When set to stream, streaming is used whenever the server supports it. The default auto mode behaves like poll on FaaS platforms and like stream otherwise.

[Copilot]

Pull request overview

Adds support for a new serverMonitoringMode URI/client option to control whether the driver uses SDAM streaming (awaitable hello) vs polling, and updates unified test runner support for SDAM/heartbeat events.

Changes:

• Add serverMonitoringMode parsing/stringifying via Mongo::URI::OptionsMapper, plus URI spec coverage (valid values, case-insensitivity, invalid value warning).
• Gate push monitor (streaming) startup in Mongo::Server::Monitor behind a new streaming_enabled? decision.
• Extend unified spec runner/assertions to subscribe to server heartbeat events, filter SDAM events, and assert the awaited field.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
spec/runners/unified/test.rb	Subscribes unified runner to SERVER_HEARTBEAT events when requested.
spec/runners/unified/assertions.rb	Adds SDAM event filtering and awaited assertion support.
spec/mongo/uri_spec.rb	Adds tests for serverMonitoringMode URI option parsing/roundtripping/warnings.
spec/mongo/server/monitor_spec.rb	Adds unit tests for Monitor#streaming_enabled? across modes and environments.
lib/mongo/uri/options_mapper.rb	Introduces serverMonitoringMode option mapping and value conversion/stringification.
lib/mongo/uri.rb	Defines SERVER_MONITORING_MODES accepted values for URI parsing.
lib/mongo/server/monitor.rb	Adds streaming_enabled? and uses it to enable/disable push monitoring.
lib/mongo/client.rb	Adds :server_monitoring_mode to VALID_OPTIONS.

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[Copilot]

streaming_enabled? can return nil if :server_monitoring_mode is set to an unexpected value (e.g. a String like "poll" or any other symbol), because the case has no else. This makes the method violate its boolean contract and will implicitly disable streaming without any warning. Consider normalizing string values (e.g. downcase+to_sym) and adding an else branch that logs a warning and defaults to :auto (or raises) so the return value is always true/false.