整合求解器活动监控与步长回归证据

同步远端 PNL0003 诊断和大采样网格能力，语义合并活动感知的 60 秒真停滞判定与旧后端 15 分钟兼容兜底。

纳管热路径优化、15 单元运行证据、浏览器与 API 报告，并补充北京时间更新日志和遗留问题。

tests/test_test_mql_8_regression.py

@@ -110,6 +110,62 @@ class TestMql8StaticRegressionTests(unittest.TestCase):
             expected["hasMechanicalStateEvents"],
         )
 
+    def test_contact_aware_mechanical_tolerance_plan_is_proof_gated(self) -> None:
+        assert self.validation.document is not None
+        system = GenericFluidSystem(
+            compile_system_xml_network(self.validation.document)
+        )
+        reducer = system.mechanical_state_reducer
+
+        plan = reducer.absolute_tolerance_plan(
+            1.0e-8,
+            mode="contact-aware-v1",
+        )
+        diagnostics = plan.as_dict()
+        self.assertEqual(len(plan.values), len(system.initial_state_vector()))
+        self.assertEqual(diagnostics["groupCount"], 10)
+        self.assertEqual(diagnostics["eligibleGroupCount"], 8)
+        self.assertEqual(diagnostics["relaxedVelocityStateCount"], 8)
+        self.assertEqual(diagnostics["relaxedPositionStateCount"], 0)
+
+        by_component = {
+            group.components[0]: group
+            for group in plan.groups
+        }
+        for index in range(1, 9):
+            group = by_component[f"amesim_mecmas21_{index}"]
+            self.assertTrue(group.eligible)
+            self.assertEqual(group.reason, "eligibleFlexibleContact")
+            self.assertAlmostEqual(group.velocity_atol, 1.0e-10)
+            self.assertEqual(group.position_atol, 1.0e-12)
+            self.assertAlmostEqual(
+                group.minimum_damping_strength_ratio,
+                10.0,
+            )
+            self.assertAlmostEqual(
+                group.minimum_force_limited_velocity_atol,
+                1.0e-10,
+            )
+            self.assertEqual(
+                group.contacts,
+                (f"amesim_lstp00a_{index}",),
+            )
+        for index in (9, 10):
+            group = by_component[f"amesim_mecmas21_{index}"]
+            self.assertFalse(group.eligible)
+            self.assertEqual(group.reason, "discreteEndstop")
+            self.assertEqual(group.velocity_atol, 1.0e-12)
+            self.assertEqual(group.position_atol, 1.0e-12)
+
+        legacy = reducer.absolute_tolerance_plan(1.0e-8, mode="legacy")
+        self.assertTrue(
+            all(
+                group.velocity_atol == 1.0e-12
+                and group.position_atol == 1.0e-12
+                for group in legacy.groups
+            )
+        )
+
     def test_signal_event_schedule_is_fixed_for_every_horizon(self) -> None:
         assert self.validation.document is not None
         system = GenericFluidSystem(