Add management fee callbacks

crates/fidc-core/tests/engine_hooks.rs

@@ -525,11 +525,23 @@ impl Strategy for AccountFlowStrategy {
                     receiving_days: 1,
                     reason: "cash_in_next_day".to_string(),
                 },
+                OrderIntent::SetManagementFeeRate {
+                    rate: 0.01,
+                    reason: "enable_fee".to_string(),
+                },
             ],
             notes: Vec::new(),
             diagnostics: Vec::new(),
         })
     }
+
+    fn management_fee(
+        &mut self,
+        _ctx: &StrategyContext<'_>,
+        _rate: f64,
+    ) -> Result<Option<f64>, fidc_core::BacktestError> {
+        Ok(Some(42.0))
+    }
 }
 
 #[test]
@@ -1489,10 +1501,10 @@ fn engine_applies_account_cash_flow_and_financing_intents() {
 
     let result = engine.run().expect("backtest run");
 
-    assert!((result.equity_curve[0].cash - 11_500.0).abs() < 1e-6);
-    assert!((result.equity_curve[0].total_equity - 10_500.0).abs() < 1e-6);
-    assert!((result.equity_curve[1].cash - 12_500.0).abs() < 1e-6);
-    assert!((result.equity_curve[1].total_equity - 11_500.0).abs() < 1e-6);
+    assert!((result.equity_curve[0].cash - 11_458.0).abs() < 1e-6);
+    assert!((result.equity_curve[0].total_equity - 10_458.0).abs() < 1e-6);
+    assert!((result.equity_curve[1].cash - 12_416.0).abs() < 1e-6);
+    assert!((result.equity_curve[1].total_equity - 11_416.0).abs() < 1e-6);
     assert!(result.account_events.iter().any(|event| {
         event
             .note
@@ -1508,10 +1520,18 @@ fn engine_applies_account_cash_flow_and_financing_intents() {
             .note
             .contains("deposit_withdraw_settled amount=1000.00")
     }));
+    assert!(result.account_events.iter().any(|event| {
+        event
+            .note
+            .contains("management_fee rate=0.010000 fee=42.00")
+    }));
     assert!(result.process_events.iter().any(|event| {
         event.kind == ProcessEventKind::AccountFinanceRepay
             && event.detail.contains("liabilities_after=1000.00")
     }));
+    assert!(result.process_events.iter().any(|event| {
+        event.kind == ProcessEventKind::AccountManagementFee && event.detail.contains("fee=42.00")
+    }));
 }
 
 #[test]