fix tests: update merge tests for private→unlisted rename and client-side filtering

tests/test_merge.py

@@ -88,7 +88,7 @@ def test_apply_sidecar_body_takes_precedence_over_fm_description():
 
 def test_apply_sidecar_private_flag():
     result = apply_sidecar(BASE_DETAIL, {"private": True}, "")
-    assert result["privacy"] == "private"
+    assert result["privacy"] == "unlisted"
 
 
 def test_apply_sidecar_highlight():
@@ -177,9 +177,11 @@ def test_merge_all_private_filtered_from_index(data_dir):
     merge_all(data_dir)
 
     index = json.loads((data_dir / "_merged" / "index.json").read_text())
-    ids = [a["id"] for a in index["activities"]]
-    assert "2024-01-01T080000Z-morning-ride" not in ids
-    assert "2024-01-02T090000Z-easy-run" in ids
+    activities = {a["id"]: a for a in index["activities"]}
+    # unlisted activities are kept in the index; filtering is client-side
+    assert "2024-01-01T080000Z-morning-ride" in activities
+    assert activities["2024-01-01T080000Z-morning-ride"]["privacy"] == "unlisted"
+    assert "2024-01-02T090000Z-easy-run" in activities
 
 
 def test_merge_all_highlight_sorts_first(data_dir):