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。

app/simulation/components/amesim/flow/orifices.py

@@ -60,6 +60,9 @@ class AmesimPnor001(AlgebraicComponent):
     MODEL_TYPE = "amesim_pnor001"
     MODEL_VERSION = "0.3.0"
     PRESSURE_FLOW_DEPENDS_ON_STREAM = True
+    PRESSURE_FLOW_EXACT_SUM_TO_ZERO_EQUATION_SUFFIXES = frozenset(
+        ("mass_flow_balance",)
+    )
     PORTS = (
         PortDefinition.pneumatic("port_1", nominal_role="bidirectional"),
         PortDefinition.pneumatic("port_2", nominal_role="bidirectional"),
@@ -465,6 +468,9 @@ class AmesimPnvo001FixedOpening(AlgebraicComponent):
     MODEL_TYPE = "amesim_pnvo001_fixed"
     MODEL_VERSION = "0.2.0"
     PRESSURE_FLOW_DEPENDS_ON_STREAM = True
+    PRESSURE_FLOW_EXACT_SUM_TO_ZERO_EQUATION_SUFFIXES = frozenset(
+        ("mass_flow_balance",)
+    )
     PORTS = (
         PortDefinition.pneumatic("port_2", nominal_role="bidirectional"),
         PortDefinition.pneumatic("port_3", nominal_role="bidirectional"),
@@ -900,6 +906,10 @@ class AmesimPnvo001SignalOpening(AmesimPnvo001FixedOpening):
     MODEL_TYPE = "amesim_pnvo001"
     MODEL_VERSION = "0.2.0"
     PRESSURE_FLOW_DEPENDS_ON_STREAM = True
+    # Repeat the exact-sum promise on this concrete subclass deliberately.
+    PRESSURE_FLOW_EXACT_SUM_TO_ZERO_EQUATION_SUFFIXES = frozenset(
+        ("mass_flow_balance",)
+    )
     PORTS = (
         PortDefinition.signal("res", nominal_role="input"),
         PortDefinition.pneumatic("port_2", nominal_role="bidirectional"),