feat(workflow_engine): Add in hook for producing occurrences from the stateful detector

[everettbu]

Test 10

[Copilot]

Pull Request Overview

This PR introduces a hook for producing occurrences from the stateful detector by adding a new abstract method to generate issue occurrences and updating the detector evaluation process to handle occurrence creation.

• Adds a new abstract method build_occurrence_and_event_data() to the StatefulDetectorHandler class
• Updates the detector evaluation logic to create occurrences when detectors become active (non-OK status)
• Modifies the return type of evaluate() methods from lists to dictionaries for better group key management

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/sentry/workflow_engine/processors/detector.py	Adds occurrence creation hook and updates evaluation logic to use dictionaries
src/sentry/workflow_engine/models/detector.py	Adds group_type property for accessing detector's group type
src/sentry/incidents/grouptype.py	Updates MetricAlertDetectorHandler to inherit from StatefulDetectorHandler
tests/sentry/workflow_engine/processors/test_detector.py	Updates tests to handle new dictionary return types and adds occurrence verification

Comments suppressed due to low confidence (2)

src/sentry/workflow_engine/processors/detector.py:289

• The variable name 'result' is ambiguous since it shadows the existing 'result' variable that was assigned None on line 289. Consider using a more specific name like 'occurrence_or_status_change' or 'detector_result'.

            result: StatusChangeMessage | IssueOccurrence

src/sentry/incidents/grouptype.py:11

• The MetricAlertDetectorHandler class inherits from StatefulDetectorHandler but doesn't implement the required abstract methods. This will cause runtime errors when instantiated. The class needs to implement 'get_dedupe_value', 'get_group_key_values', and 'build_occurrence_and_event_data' methods.

class MetricAlertDetectorHandler(StatefulDetectorHandler[QuerySubscriptionUpdate]):