test: fix resolve_model_provider mocks to accept explicitly_picked kwarg

Two streaming tests monkeypatch resolve_model_provider with a fixed-arg lambda
(_model only). The send path now calls it with explicitly_picked=, so the mocks
raised TypeError. Widened both lambdas to (_model, **_kw). Caught by the full
suite (not the focused resolver tests, which call the real function).

tests/test_issue1897_profile_switch_agent_cache.py

@@ -156,7 +156,7 @@ def test_same_session_profile_switch_rebuilds_agent_under_new_soul_home(tmp_path
     monkeypatch.setattr(
         streaming,
         "resolve_model_provider",
-        lambda _model: ("test-model", "test-provider", None),
+        lambda _model, **_kw: ("test-model", "test-provider", None),
     )
     monkeypatch.setattr(streaming, "_maybe_schedule_title_refresh", lambda *args, **kwargs: None)
     monkeypatch.setattr(profiles, "get_hermes_home_for_profile", home_for_profile)

tests/test_issue2965_streaming_sessiondb_profile_home.py

@@ -129,7 +129,7 @@ def test_streaming_sessiondb_uses_session_profile_state_db(tmp_path, monkeypatch
     monkeypatch.setattr(
         streaming,
         "resolve_model_provider",
-        lambda _model: ("test-model", "test-provider", None),
+        lambda _model, **_kw: ("test-model", "test-provider", None),
     )
     monkeypatch.setattr(streaming, "_maybe_schedule_title_refresh", lambda *args, **kwargs: None)
     monkeypatch.setattr(profiles, "get_hermes_home_for_profile", lambda _profile: profile_home)