feat(enterprise): Add OTEL telemetry with slim traces, metrics, and structured logs

- Add EnterpriseOtelTrace handler with span emission for workflows and nodes
- Implement minimal-span strategy: slim spans + detailed companion logs
- Add deterministic span/trace IDs for cross-workflow trace correlation
- Add metric collection at 100% accuracy (counters & histograms)
- Add event handlers for app lifecycle and feedback telemetry
- Add cross-workflow trace linking with parent context propagation
- Add OTEL exporter with configurable sampling and privacy controls
- Wire enterprise telemetry into workflow execution pipeline
- Add telemetry configuration in enterprise configs

api/events/app_event.py

@@ -3,6 +3,12 @@ from blinker import signal
 # sender: app
 app_was_created = signal("app-was-created")
 
+# sender: app
+app_was_deleted = signal("app-was-deleted")
+
+# sender: app
+app_was_updated = signal("app-was-updated")
+
 # sender: app, kwargs: app_model_config
 app_model_config_was_updated = signal("app-model-config-was-updated")
 

api/events/feedback_event.py

@@ -0,0 +1,4 @@
+from blinker import signal
+
+# sender: MessageFeedback, kwargs: tenant_id
+feedback_was_created = signal("feedback-was-created")