Add workspace database schema

This adds the required workspace columns and the workspace catalog table
with the default workspace precreated. All workspace columns default to
"default" for now and we may choose to remove the defaults once the
tracking store and model registry store are made workspace aware to
catch application logic issues not properly setting the workspace.

Author: mprahl

docs/api_reference/api_inventory.txt

@@ -528,6 +528,7 @@ mlflow.entities.WebhookStatus.to_proto
 mlflow.entities.WebhookTestResult
 mlflow.entities.WebhookTestResult.from_proto
 mlflow.entities.WebhookTestResult.to_proto
+mlflow.entities.Workspace
 mlflow.entities.assessment.Assessment
 mlflow.entities.assessment.Expectation
 mlflow.entities.assessment.Feedback
@@ -627,6 +628,7 @@ mlflow.entities.webhook.Webhook
 mlflow.entities.webhook.WebhookEvent
 mlflow.entities.webhook.WebhookStatus
 mlflow.entities.webhook.WebhookTestResult
+mlflow.entities.workspace.Workspace
 mlflow.evaluate
 mlflow.exceptions.get_error_code
 mlflow.finalize_logged_model

mlflow/entities/__init__.py

@@ -62,6 +62,7 @@
     WebhookStatus,
     WebhookTestResult,
 )
+from mlflow.entities.workspace import Workspace
 
 __all__ = [
     "Experiment",
@@ -125,6 +126,7 @@
     "WebhookEvent",
     "WebhookStatus",
     "WebhookTestResult",
+    "Workspace",
 ]
 
 

mlflow/entities/workspace.py

@@ -0,0 +1,13 @@
+"""Workspace entity shared between server and stores."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True, slots=True)
+class Workspace:
+    """Minimal metadata describing a workspace."""
+
+    name: str
+    description: str | None = None