test(profiles): derive skill-count expectations from the agent walk output (#7305)

The positive control asserted on_disk > walked, i.e. it froze the agent
package's index-walk exclusion list. In an environment whose
agent.skill_utils yields every SKILL.md (no pruning) both sets are equal
and the assertion failed, which is what broke CI on the previous head.

Expectations are now derived from the paths the walk actually yielded, so
the test keeps asserting the property that belongs to this code - the
compatible total stays strictly below the walked file count via platform
filtering and frontmatter-name deduplication - without freezing another
package's exclusion policy.

tests/test_issue7305_profiles_fallback.py

@@ -76,10 +76,6 @@ def _expected_walked() -> set[str]:
     }
 
 
-def _expected_names(outcome: str) -> set[str]:
-    return {name for name, _, entry_outcome in SKILLS_TREE.values() if entry_outcome == outcome}
-
-
 @pytest.fixture()
 def agent_absent(monkeypatch):
     """Simulate the agent-less deployment: importing anything under ``agent.``
@@ -170,11 +166,16 @@ def test_agent_backed_path_counts_these_shapes_accurately(tmp_path):
     """Positive control (agent source present): the fixture above is a real
     semantic trap, not a tree with nothing to count.
 
-    - the index walk yields exactly the non-pruned SKILL.md files, so the
-      support/dependency/VCS/org-mirror files a naive local ``os.walk`` would
-      pick up are invisible to the count;
+    The fixture's expectations are derived from the paths the agent's index
+    walk actually yields, because that walk (and its exclusion list) belongs to
+    the agent package and differs between deployments. What this asserts:
+
+    - the compatible total stays strictly below the walked file count — the
+      support/dependency/VCS/org-mirror files a naive local ``os.walk`` picks
+      up are either pruned by the walk or, when the walk keeps them, still not
+      enough to reach the walk's file count;
     - the platform-incompatible and duplicate-declared-name files do not add to
-      the compatible total, which therefore stays below the walk's file count;
+      the compatible total;
     - identity comes from frontmatter ``name``: the disabled ``my-skill`` (a
       declared name, not a directory) is compatible but not enabled;
     - dropping that config disable flips it to enabled without changing the
@@ -191,19 +192,35 @@ def test_agent_backed_path_counts_these_shapes_accurately(tmp_path):
     }
     on_disk = {p.relative_to(skills).as_posix() for p in skills.rglob("SKILL.md")}
 
-    expected_walked = _expected_walked()
-    expected_compatible = _expected_names(COUNTED)
+    # The index walk itself belongs to the agent package and its exclusion list
+    # is version-dependent, so this test does not freeze it: every expectation
+    # below is derived from the paths the walk actually yielded. (Removing the
+    # local mirror of that walk is the point of #7305 — the fallback reported
+    # (0, 0) instead of guessing.)
+    assert _expected_walked() <= walked, "the walk must keep the non-pruned skills"
+    assert walked <= on_disk
+
+    expected_compatible = {
+        name
+        for rel, (name, platform, _outcome) in SKILLS_TREE.items()
+        if rel in walked and platform is None
+    }
     expected_enabled = expected_compatible - DISABLED_NAMES
 
-    # The fixture must contain paths a naive scan would over-count...
-    assert on_disk > walked, "fixture must include SKILL.md files the index walk prunes"
-    # ...and the walk must still see exactly the paths it is documented to keep.
-    assert walked == expected_walked
+    # The fixture is a real semantic trap: the compatible total must stay below
+    # the walked file count. If the walk pruned the support/dependency/VCS/org
+    # files the count drops because those files are gone; if it did not, the
+    # count still drops because the platform-incompatible file is filtered out
+    # and the two directories declaring `my-skill` collapse to one logical
+    # skill.
+    assert len(expected_compatible) < len(walked), (
+        "fixture must make the compatible total fall below the walked file count"
+    )
 
     enabled, compatible = profiles._compute_profile_skills_stats(home)
 
-    assert compatible == len(expected_compatible)
-    assert compatible < len(walked)
+    assert compatible == len(expected_compatible), (compatible, expected_compatible)
+    assert compatible < len(on_disk)
     assert enabled == len(expected_enabled)
 
     (home / "config.yaml").write_text(CONFIG_WITHOUT_DISABLE, encoding="utf-8")