feat(detectors): Handle config field updates in base detector validator (#103184)

Previously, the base detector validator update() method did not handle
config field updates at all. This adds proper support for updating the
config field with JSON schema validation using enforce_config_schema().

Adds tests to verify:
- Valid config updates are applied correctly
- Invalid config updates that violate the schema are rejected with
appropriate error messages

Author: evanpurkhiser

src/sentry/workflow_engine/endpoints/validators/base/detector.py

@@ -133,6 +133,14 @@ def update(self, instance: Detector, validated_data: dict[str, Any]):
                     group_validator = BaseDataConditionGroupValidator()
                     group_validator.update(instance.workflow_condition_group, condition_group)
 
+            # Handle config field update
+            if "config" in validated_data:
+                instance.config = validated_data.get("config", instance.config)
+                try:
+                    enforce_config_schema(instance)
+                except JSONSchemaValidationError as error:
+                    raise serializers.ValidationError({"config": [str(error)]})
+
             instance.save()
 
         create_audit_entry(

tests/sentry/workflow_engine/endpoints/test_organization_detector_details.py

@@ -709,6 +709,59 @@ def test_update_workflows_no_changes(self) -> None:
                 == 0
             )
 
+    def test_update_config_valid(self) -> None:
+        """Test updating detector config with valid schema data"""
+        # Initial config
+        initial_config = {"detection_type": "static", "comparison_delta": None}
+        self.detector.config = initial_config
+        self.detector.save()
+
+        # Update with valid new config
+        updated_config = {"detection_type": "dynamic", "comparison_delta": 3600}
+        data = {
+            "config": updated_config,
+        }
+
+        with self.tasks():
+            response = self.get_success_response(
+                self.organization.slug,
+                self.detector.id,
+                **data,
+                status_code=200,
+            )
+
+        self.detector.refresh_from_db()
+        # Verify config was updated in database (snake_case)
+        assert self.detector.config == updated_config
+        # API returns camelCase
+        assert response.data["config"] == {
+            "detectionType": "dynamic",
+            "comparisonDelta": 3600,
+        }
+
+    def test_update_config_invalid_schema(self) -> None:
+        """Test updating detector config with invalid schema data fails validation"""
+        # Config missing required field 'detection_type'
+        invalid_config = {"comparison_delta": 3600}
+        data = {
+            "config": invalid_config,
+        }
+
+        with self.tasks():
+            response = self.get_error_response(
+                self.organization.slug,
+                self.detector.id,
+                **data,
+                status_code=400,
+            )
+
+        assert "config" in response.data
+        assert "detection_type" in str(response.data["config"])
+
+        # Verify config was not updated
+        self.detector.refresh_from_db()
+        assert self.detector.config != invalid_config
+
 
 @region_silo_test
 class OrganizationDetectorDetailsDeleteTest(OrganizationDetectorDetailsBaseTest):