fix: align PNL0001 symbol causality

frontend/src/componentSymbols/pneumatic.tsx

@@ -205,11 +205,11 @@ export function AmesimPnl00rSymbol() {
   );
 }
 
-/** C-R dynamic pneumatic line (AMESim PNL0001). */
+/** C-R dynamic pneumatic line (AMESim PNL0001): port 1 is R, port 2 is C. */
 export function AmesimPnl0001Symbol() {
   return (
     <SymbolSvg className="component-symbol-amesim-pnl0001-svg" domain="pneumatic">
-      <PipeNetworkBody sections={["C", "R"]} />
+      <PipeNetworkBody sections={["R", "C"]} />
     </SymbolSvg>
   );
 }

frontend/tests/e2e/component-symbols.spec.ts

@@ -2575,6 +2575,14 @@ test("PNL00R 与 PNL0001-0003 使用 standard 画布和 60% 工作区占比", as
       };
     });
     expect(geometry.occupancy).toBeCloseTo(0.6, 4);
+    if (modelType === "amesim_pnl0001") {
+      const causalLabels = symbol.locator("text");
+      await expect(causalLabels).toHaveText(["R", "C"]);
+      const labelPositions = await causalLabels.evaluateAll((labels) =>
+        labels.map((label) => Number(label.getAttribute("x"))),
+      );
+      expect(labelPositions[0]).toBeLessThan(labelPositions[1]);
+    }
   }
 });