QTZPOC-20

QTZPOC-20: Implement explicit joblib model flavor and enhance model import workflow with extensive E2E tests.

This commit introduces a first-class joblib model flavor for direct loading and saving of Python pickle artifacts, including custom code within the artifact's code/ directory, bypassing MLflow's flavor loaders. The model import workflow's status database configuration is now streamlined to default to the POSTGRES_* server, with explicit IMPORT_STATUS_DB_* overrides.

Comprehensive end-to-end tests have been added for the model import workflow, covering success paths, gate rejections, digest enforcement, provisioning failures, status record integrity, cleanup, and retry/recovery scenarios using a real-clock environment. New E2

laborious/activities/activities.py

@@ -82,8 +82,8 @@ class Activities(Storage, MLFlow, Gates, OPC, ModelMetrics, API, ModelImport):
                 notification handler keeps its own client either way.
             import_config: `build_import_config()`; read from the environment when absent
             import_status_config: `build_import_status_config()`; read from the environment when
-                absent. This is the BFF database holding the import log, a second Postgres
-                connection that is never the one Storage holds.
+                absent. This is the BFF database holding the import log: another database on the
+                `POSTGRES_*` server, and a second connection that is never the one Storage holds.
 
         Raises:
             Exception: If any parent class initialization fails

laborious/activities/model_import.py

@@ -288,8 +288,10 @@ class ModelImport(SientiaMonitoring):
         """
         Args:
             status_config: `build_import_status_config()` — the BFF database holding the import log.
-                This is a **second** Postgres connection, independent of the one Laborious already
-                holds, which is what makes the transactional independence of design D7 literal.
+                This is a **second** Postgres connection — another database, on the `POSTGRES_*`
+                server unless the IMPORT_STATUS_DB_* overrides move it — and its separateness from
+                the one Laborious already holds is what makes design D7's transactional
+                independence literal.
             import_config: `build_import_config()` — bucket, prefix, ceilings, work directory,
                 envelope key and the models collection name.
             minio_repository: the shared MinIO repository, for the uploaded bundle.