QTZPOC-20

QTZPOC-20: Implement model import workflow for .sientia bundles

Introduces the import_model workflow and its associated activities to enable importing .sientia bundles into MLflow and MongoDB. This includes:

*   New core workflow and activity logic for handling bundle download, decryption, validation, MLflow provisioning (experiments, runs, registered versions), and MongoDB model document creation.
*   Comprehensive E2E and unit test suites, including a dedicated test harness and a manual run script for development.
*   Updated .env.example and README.md with new configurations and usage instructions.
*   Ensures correct MLflow model source resolution for legacy loader compatibility and robust MongoDB document management.
*   Refactors existing utility scripts into a scripts/ directory.

laborious/workflows/import_model.py

@@ -356,7 +356,9 @@ class ImportModel:
                 start_to_close_timeout=STATUS_WRITE_TIMEOUT,
                 schedule_to_close_timeout=STATUS_WRITE_ENVELOPE,
             )
-        except BaseException as error:  # NOSONAR - the outcome stands even when it cannot be written
+        except (
+            BaseException
+        ) as error:  # NOSONAR - the outcome stands even when it cannot be written
             await self._report_status_write_failure(
                 base,
                 error,
@@ -377,7 +379,9 @@ class ImportModel:
                 retry_policy=retry_policy,
                 start_to_close_timeout=STATUS_WRITE_TIMEOUT,
             )
-        except BaseException:  # NOSONAR - reporting the report is where this stops
+        except BaseException:  # noqa: S110  # NOSONAR - the report of a report is where this stops
+            # Deliberately silent: the channel this was trying to reach is the thing that logs, so
+            # there is nowhere left to say it, and an import that worked must not fail over it.
             pass
 
     # ----------------------------------------------------------- side-effect steps
@@ -389,8 +393,8 @@ class ImportModel:
         The rule is applied by the importer rather than assumed from a Helm value, so the acceptance
         criterion is verifiable from the code that depends on it. But a bucket policy the importer
         cannot set is an operational problem, not a bad import: failing a valid model import because
-        a lifecycle API refused would be the wrong trade, so this is reported and dropped like a
-        lost status hint.
+        a lifecycle API refused would be the wrong trade, so the failure is dropped here and left
+        where Temporal already records it — the activity's own failure in the event history.
         """
         try:
             await workflow.execute_activity_method(
@@ -399,7 +403,11 @@ class ImportModel:
                 retry_policy=retry_policy,
                 start_to_close_timeout=RETENTION_TIMEOUT,
             )
-        except BaseException:  # NOSONAR - retention is not a precondition of a correct import
+        except BaseException:  # noqa: S110  # NOSONAR - retention is not a precondition of an import
+            # Dropped, not reported: the activity's own failure is already in the event history,
+            # and a bucket policy the importer cannot set is an operational problem rather than a
+            # bad import. Failing a valid model import over a lifecycle API would be the wrong
+            # trade.
             pass
 
     @staticmethod