test: no test throws a response away; the stream session is narrowed, not baselined

The 7 baselined Optional accesses in plex/stream.py were one fact the type did not carry: the
initial spawn (replace_only=None) always supersedes, so only the fallback respawn can get None.
An assert at the call site says so; the pyright baseline drops 195 -> 188.

test_abuse_limits: the public-URL and YouTube enqueue tests stopped at the profile lookup
(400 no_profile) and passed on that unrelated refusal. They now send an inline spec and assert
the job is queued. The same shape — a request whose response is discarded — sat at 53 more
places across the suite (all returned what they should, measured with a TestClient probe);
each now asserts its status, and test_response_checked keeps it that way (seen red).

backend/tests/test_saved_views_source.py

@@ -53,8 +53,8 @@ def test_default_is_per_source(db, monkeypatch, override_dep):
     pid = c.post("/api/saved-views", json={"name": "P", "filters": {}, "source": "plex"}).json()[
         "id"
     ]
-    c.patch(f"/api/saved-views/{fid}", json={"is_default": True})
-    c.patch(f"/api/saved-views/{pid}", json={"is_default": True})
+    assert c.patch(f"/api/saved-views/{fid}", json={"is_default": True}).status_code == 200
+    assert c.patch(f"/api/saved-views/{pid}", json={"is_default": True}).status_code == 200
     # Making the Plex view default must NOT clear the feed view's default (different source).
     assert c.get("/api/saved-views?source=feed").json()[0]["is_default"] is True
     assert c.get("/api/saved-views?source=plex").json()[0]["is_default"] is True