fix: expose run step identities across transports

src/wf_api/models/runs.py

@@ -48,6 +48,7 @@ class TraceEntryPayload(TypedDict):
     frame_id: str
     node_id: str
     step_type: str
+    step_number: int | None
     resolved_input: JsonObject
     outcome: str
     next_node_id: str

src/wf_transport_rpc_http/models.py

@@ -438,6 +438,7 @@ class StartRunParams(RpcParamsModel):
     max_steps: int | None = Field(
         default=None,
         ge=1,
+        strict=True,
         description=(
             "Optional run step budget. The server default applies when omitted; "
             "resume never accepts a replacement."