fix: make workflow drafts explicitly opt in

docs/wf_api_architecture.md

@@ -110,19 +110,34 @@ new dependency, add a narrow protocol or explicit field.
 
 ## Python client lifecycle
 
-The Python client makes the intended application flow explicit:
+Hypothetically, an application that wants to turn a discovered capability into
+a durable run would use the following complete flow:
 
 ```python
+from wf_authoring import input_from, input_value, output_to, state_path
+
 app = App.from_http_jsonrpc("http://localhost:8765/rpc")
 capability = await app.capability("wf.std.constant")
 graph = app.new_workflow(
     "example",
-    input_schema=InputModel,
-    state_schema=StateModel,
-    output_schema=OutputModel,
+    input_schema={"type": "object", "properties": {}},
+    state_schema={"type": "object", "properties": {"value": {"type": "string"}}},
+    output_schema={
+        "type": "object",
+        "properties": {"value": {"type": "string"}},
+        "required": ["value"],
+    },
 )
-step = graph.use(capability)
+step = graph.use(
+    capability,
+    id="constant",
+    input=[input_value("value", "hello")],
+    output=[output_to("value", state_path("value"))],
+)
+end = graph.end("ok", id="end_ok")
 graph.set_entry_point(step)
+graph.connect(step, "ok", end)
+graph.set_output([input_from(state_path("value"), "value")])
 validation = await graph.validate()
 validation.raise_for_errors()
 artifact = await graph.save(version=1)
@@ -189,8 +204,8 @@ contract itself.
 ```text
 WorkflowApi
   capabilities: WorkflowCapabilityApi
-  drafts: WorkflowDraftApi
-  draft_authoring: WorkflowDraftAuthoringApi
+  drafts: WorkflowDraftApi | None  # only when drafts=True
+  draft_authoring: WorkflowDraftAuthoringApi | None  # only when drafts=True
   artifacts: WorkflowArtifactApi
   deployments: WorkflowDeploymentApi
   runs: WorkflowRunApi