fix(learn): v1 withholds verify.flag_b and ms.operation (plane-profile leak audit)

Maintainer decision 2026-10-02. Not pushed with the release; main is otherwise
at v2.0.0.

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

src/openultrasast/learn/schema.py

@@ -102,7 +102,12 @@ EXCLUDED_FIELDS = frozenset(
 # Entries name an instrument (all its state and values) or a single feature. v1 withholds the engine and the function
 # length: both separate fixed from vulnerable pair sides by construction (a fix removes a sink, a guard lengthens the
 # function), not by anything that holds on unseen code (leak audit 2026-10-01).
-INPUT_PROFILES: Mapping[str, tuple[str, ...]] = {"v1": ("engine", "facts.function_lines"), "full": ()}
+# The plane profile also withholds verify.flag_b and ms.operation in v1 (maintainer decision 2026-10-02 on the
+# slice-2 leak audit: they separate pair sides because a fix removes the sink, which does not hold on unseen code).
+INPUT_PROFILES: Mapping[str, tuple[str, ...]] = {
+    "v1": ("engine", "facts.function_lines", "verify.flag_b", "ms.operation"),
+    "full": (),
+}
 DEFAULT_INPUTS = "v1"
 
 

tests/test_learn_leaks.py

@@ -113,3 +113,13 @@ def test_v1_withholds_function_length_from_prompts_and_distance() -> None:
     assert "facts.function_lines: 42" in render_signals(a["x"], a["instruments"], "static", inputs="full")
     assert gower(a["x"], a["instruments"], b["x"], b["instruments"], "static") == 0.0
     assert gower(a["x"], a["instruments"], b["x"], b["instruments"], "static", inputs="full") > 0.0
+
+
+def test_v1_withholds_the_plane_profile_leak_signals() -> None:
+    """Slice-2 leak audit (2026-10-02): verify.flag_b and ms.operation track the pair label in the plane profile;
+    v1 renders neither and the distance ignores both, while ``full`` keeps them."""
+    from openultrasast.learn.schema import withheld
+
+    hidden = withheld("v1")
+    assert {"verify.flag_b", "ms.operation", "engine", "facts.function_lines"} <= hidden
+    assert withheld("full") == frozenset()