Display executionPlan in UI; add tests for Trader executionPlan parsing and TradingGraph execution step

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/agents/__tests__/trader.test.ts

@@ -36,4 +36,32 @@ describe("Trader", () => {
     const decision = await trader.decide("AAPL", mockReports, mockDebates);
     expect(decision.action).toBe("buy");
   });
+
+  it("parses executionPlan on sell", async () => {
+    const mockSellClient = {
+      createChatCompletion: vi.fn().mockResolvedValue({
+        choices: [{ message: { content: JSON.stringify({
+          action: "sell",
+          confidence: 0.9,
+          reasoning: "Exit position",
+          executionPlan: {
+            amount: 50,
+            riskManagement: { maxLossPercent: 1.5, method: "trailing" },
+            takeProfit: 150,
+            note: "Test plan"
+          }
+        }) } }]
+      }),
+    };
+
+    const trader = new Trader(mockSellClient as any);
+    const decision = await trader.decide("AAPL", mockReports, mockDebates);
+
+    expect(decision.action).toBe("sell");
+    expect(decision.executionPlan).toBeDefined();
+    expect(decision.executionPlan?.amount).toBe(50);
+    expect(decision.executionPlan?.takeProfit).toBe(150);
+    expect(decision.executionPlan?.riskManagement?.maxLossPercent).toBe(1.5);
+  });
+  });
 });