test(recipe): deselect the FTS wall-clock benchmarks by default

TestRecipeFTSIndexPerformance asserts a 100ms bound on a ~1ms search. On shared CI runners that flakes: the same test measured 0.12s and 0.14s on two consecutive main pushes while the code around it did not change.

Mark the class with the existing performance marker (pytest.ini already runs with -m "not performance"), matching tests/performance/. Run them explicitly with pytest -m performance.

tests/services/test_recipe_fts_index.py

@@ -470,8 +470,12 @@ class TestRecipeFTSIndexSpecialCharacters:
         # Note: Result depends on FTS5 configuration
 
 
+# Wall-clock bounds are unreliable on shared CI runners: a ~1ms search flaked
+# at 0.12-0.14s against the 100ms threshold. Deselected by default; run with
+# `pytest -m performance`.
+@pytest.mark.performance
 class TestRecipeFTSIndexPerformance:
-    """Basic performance tests."""
+    """Basic performance tests (run with ``-m performance``)."""
 
     def test_build_large_index(self, fts_index):
         """Test building index with many recipes."""