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.

pyproject.toml

@@ -65,6 +65,11 @@ ignore = [
     # must be in sys.modules before Activities is imported, so they cannot move up.
     "E402",
 ]
+"scripts/**/*.py" = [
+    # Notebook-style scripts split into `# %%` cells: each cell imports what it needs
+    # where it needs it, so imports legitimately appear below other statements.
+    "E402",
+]
 
 [tool.ruff.lint.mccabe]
 max-complexity = 15
@@ -133,6 +138,10 @@ markers = [
     "integration: marks tests as integration tests",
     "unit: marks tests as unit tests",
     "opc: marks tests that use the in-process OPC UA server (OpcRepository E2E)",
+    # The .sientia import e2e suite. Outside `testpaths`, so `validate --only-tests` and the
+    # coverage gate never collect it; run it on request with `pytest e2e -m import_e2e`.
+    "import_e2e: marks the model-import end-to-end tests (needs Docker and an MLflow server)",
+    "slow: marks tests that run on a real clock and take tens of seconds",
 ]
 
 [tool.coverage.run]