Make lint-backend green, and regenerate the stale client

`wanted_names` never read its `previous` argument — the caller reassigns
`wanted` from the return value — so the parameter goes rather than gaining
an underscore; its one call site and four test calls follow. Sorts the
imports in test_artifacts.py. Both were failing `make lint-backend` at HEAD.

Regenerates the client, which 8cb843e left behind when it corrected the
revoke_client docstring.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CL9zvnnvcp1mvA8o7impxk

backend/fluksio/api/routes/flows.py

@@ -922,9 +922,7 @@ MAX_FRAME_EVENTS = 64
 MAX_MEDIA_NAMES = 32
 
 
-def wanted_names(
-    frame: str, only: set[str] | None, previous: set[str]
-) -> set[str] | None:
+def wanted_names(frame: str, only: set[str] | None) -> set[str] | None:
     """What this client is asking to be sent bytes for, or None if it said
     something else.
 
@@ -1061,7 +1059,7 @@ async def flow_events(websocket: WebSocket, token: str = "") -> None:
                     # say, used to be read as the client going away and cost
                     # it every live update from then on.
                     if receiver.exception() is None:
-                        asked = wanted_names(receiver.result(), only, wanted)
+                        asked = wanted_names(receiver.result(), only)
                         if asked is not None:
                             wanted = asked
                     receiver = asyncio.create_task(websocket.receive_text())

backend/tests/api/routes/test_panels.py

@@ -944,11 +944,11 @@ def test_a_socket_pushes_only_the_frames_it_was_asked_for(tmp_path) -> None:
     asking = orjson.dumps({"type": "media", "names": ["cam.frame", "other.frame"]})
     # A person's socket gets what it asked for; a panel's is intersected with
     # what it draws, so naming a message is not a way around the scope.
-    assert wanted_names(asking.decode(), None, set()) == {"cam.frame", "other.frame"}
-    assert wanted_names(asking.decode(), {"cam.frame"}, set()) == {"cam.frame"}
+    assert wanted_names(asking.decode(), None) == {"cam.frame", "other.frame"}
+    assert wanted_names(asking.decode(), {"cam.frame"}) == {"cam.frame"}
     # Anything else on this socket leaves the set alone.
-    assert wanted_names('{"type":"ping"}', None, set()) is None
-    assert wanted_names("not json", None, set()) is None
+    assert wanted_names('{"type":"ping"}', None) is None
+    assert wanted_names("not json", None) is None
 
     events = [
         {"type": "message_value", "name": "cam.frame", "value": frame, "ts": 1.0},

backend/tests/test_artifacts.py

@@ -7,7 +7,6 @@ from fastapi.testclient import TestClient
 from sqlmodel import Session, col, select
 
 from fluksio.core.config import settings
-
 from fluksio.core.db import engine as db_engine
 from fluksio.flow.artifacts import ArtifactStore, VolatileStore
 from fluksio.flow.runs import new_run_id, sweep_artifacts