SIENTIAPDE-1646

SIENTIAPDE-1646 Enhance OPC integration and E2E testing framework

- Updated .gitignore to exclude '.cursor/*' for better file management.
- Added new marker in pyproject.toml for E2E tests using OPC.
- Introduced async OPC server fixtures and improved connection handling in conftest.py.
- Enhanced error handling in OPC activities and added metrics for session management in metrics.py.
- Updated E2E tests to cover new OPC scenarios, including session errors and reconnect handling.
- Refactored helper functions to improve prediction assertion logic in helpers.py.
- Documented new OPC scenarios in scenarios.md for clarity on expected outcomes.

e2e/scenarios.md

@@ -10,6 +10,27 @@ It is a functional reference of scenario behavior, inputs, and expected outcomes
 - Tests run under `e2e/` and are marked with `@pytest.mark.integration`.
 - PostgreSQL and MinIO are provisioned with testcontainers.
 - `test_minio_offload.py` uses real MinIO I/O; other scenario suites may use stubs/mocks for optional outputs.
+- Real OPC UA scenarios use `@pytest.mark.opc` and an in-process asyncua server (`e2e/test_opc_real_server.py`).
+
+### Local validation
+
+Use the existing project virtualenv and the shared `validate` script for unit/quality gates; run E2E separately (Docker required).
+
+```bash
+source ./venv/bin/activate
+
+# Auto-fix + static checks (no pytest)
+validate --fix --project-name=laborious
+
+# Full unit + quality gate
+validate --project-name=laborious
+
+# E2E (integration)
+pytest e2e/ --override-ini testpaths=e2e -m integration
+
+# E2E (real OPC server only)
+pytest e2e/test_opc_real_server.py --override-ini testpaths=e2e -m opc
+```
 
 ---
 
@@ -195,6 +216,30 @@ Source: `e2e/test_predictions_batch_format_export.py`
 - Workflow completes.
 - Prediction persisted with PI error confidence and descriptive comment.
 
+#### 3.2.4 OPC session / channel error (confidence 14)
+**Summary**: Tier-1 `BadSessionIdInvalid` (or equivalent session error) degrades the prediction without failing the workflow.
+
+**Sources**:
+- Mock: `e2e/test_predictions_batch_format_export.py::test_scenario_3_2_4_opc_session_bad_mock`
+- Real server: `e2e/test_opc_real_server.py::test_scenario_3_2_4_opc_session_bad_real_server` (`@pytest.mark.opc`)
+
+**Expected Outcome**:
+- Workflow completes.
+- `prediction_confidence` is 14.
+- Comments contain `OPC UA session/channel error: BadSessionIdInvalid`.
+
+#### 3.2.5 OPC write blocked during reconnect (confidence 14)
+**Summary**: While reconnect holds the repository connection lock, writes fail fast with `reconnect_in_progress`.
+
+**Sources**:
+- Mock: `e2e/test_predictions_batch_format_export.py::test_scenario_3_2_5_opc_reconnect_in_progress_mock`
+- Real server: `e2e/test_opc_real_server.py::test_scenario_3_2_5_opc_write_blocked_during_reconnect_real_server` (`@pytest.mark.opc`)
+
+**Expected Outcome**:
+- Workflow completes.
+- `prediction_confidence` is 14.
+- Comments contain `OPC UA reconnect in progress`.
+
 ### 3.3.1 Combined Optional Outputs (PI + OPC)
 **Summary**: Both external output channels are enabled together.