fix(tests): F2 — the voluptuous mirror compares fields, not marker classes (t35)

real voluptuous 0.16.0 implements ``Marker.__eq__`` as ``self.schema ==
other`` — a field-name comparison with no class check, so
``Optional("x") == Required("x")`` is True (verified against the library
source, not just the audit note). The mirror compared class + field, which
kept two dict entries for one field: a ``Required(field, default=...)`` after
``Optional(field)`` LOOKED like it applied the default, while real voluptuous
keeps the first (defaultless) key object and silently drops it — the exact
t33 F-A failure mode the mirror exists to catch, i.e. the harness could mask
the bug it was built to see.

``Marker.__eq__`` is now the library's comparison and the contract tests gained
both pins: field-only equality (with equal hashes) and the mixed-marker
re-declaration that used to be masked. Reverting only ``__eq__`` makes those
two fail, which is the red proof recorded for t35.

Verified: uvx --with pytest-asyncio pytest tests -q → 276 passed, 1 skipped;
uvx ruff check custom_components tests → clean.

tests/test_config_flow_ux.py

@@ -424,6 +424,37 @@ class TestVoluptuousMirrorContract:
             vol_mirror.declared_fields({CONF_ADB_HOST: str})
 
 
+    def test_marker_equality_is_field_only_like_voluptuous(self):
+        """t35 F2: real ``Marker.__eq__`` is ``self.schema == other``.
+
+        No class check: ``Optional("x") == Required("x")`` on voluptuous 0.16.0.
+        """
+        vol = sys.modules["voluptuous"]
+
+        assert vol.Optional(CONF_ADB_HOST) == vol.Required(CONF_ADB_HOST)
+        assert hash(vol.Optional(CONF_ADB_HOST)) == hash(
+            vol.Required(CONF_ADB_HOST)
+        )
+        # the real implementation compares the field name to the other value
+        assert vol.Optional(CONF_ADB_HOST) == CONF_ADB_HOST
+
+    def test_a_mixed_marker_redeclaration_drops_the_default(self):
+        """The case a class-comparing mirror masks (t35 F2).
+
+        ``Required(field, default=...)`` after ``Optional(field)`` collides on
+        the field name, so the FIRST key object (no default) survives — the
+        schema silently loses the default, exactly like the Optional case.
+        """
+        vol = sys.modules["voluptuous"]
+        schema = {vol.Optional(CONF_ADB_HOST): str}
+        schema[vol.Required(CONF_ADB_HOST, default=DISCOVERED_HOST)] = str
+
+        assert (
+            vol_mirror.defaults_by_key(schema)[CONF_ADB_HOST]
+            is vol_mirror.UNDEFINED
+        )
+
+
 class TestDiscoveryPrefill:
     """F-A / F-A2 / F-D: the discovered address reaches the rendered FORM."""