feat: discover existing workflow objects

src/wf_client/discovery.py

@@ -0,0 +1,44 @@
+"""Lightweight immutable rows for discovering existing workflow objects."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True, slots=True)
+class ArtifactSummary:
+    """Catalog identity and display metadata for one artifact version."""
+
+    artifact_id: str
+    version: int
+    kind: str
+    title: str
+    description: str | None
+    outcomes: tuple[str, ...]
+    required_sources: tuple[str, ...]
+
+
+@dataclass(frozen=True, slots=True)
+class DeploymentSummary:
+    """Identity and binding metadata for one saved deployment."""
+
+    deployment_id: str
+    artifact_id: str
+    artifact_version: int
+    binding_count: int
+    drift_policy: str
+
+
+@dataclass(frozen=True, slots=True)
+class RunSummary:
+    """Identity and lifecycle metadata for one durable run."""
+
+    run_id: str
+    deployment_id: str
+    artifact_id: str
+    artifact_version: int
+    status: str
+    resume_readiness: str
+    diagnostic_count: int
+    created_at: str
+    updated_at: str