Add rebalance first slice (3d-7)

First vertical slice for portfolio rebalancing. Domain gains
RebalancePolicy: target-allocation validation (non-empty, per-code
shares positive two-decimal, sum exactly 100); diff computation over
the union of target and held codes (held without target = full exit)
producing BUY amount diffs and SELL unit diffs priced at the current
valuation NAV, clamped to available units, with no orders when a
weight already balances; and the deterministic idempotency key set
(rebalance:{plan}:{date}:{code} plus confirm/redeem counterparts).

Rebalance plans persist as rebalance_plans + rebalance_targets with
rebalance_idempotencies under the shared replay/conflict contract.
ExecuteRebalancePlan snapshots cash plus holdings valued at each
position's latest valuation NAV, then walks the diffs SELL-first
through the same Create/Confirm pipeline used by manual orders,
redemptions and SIP (nothing bypasses confirmation; a held code
without a valuation is skipped with an explicit marker; insufficient
cash/units fail the period visibly instead of silently trimming).

API exposes POST/GET /funds/{id}/rebalance/plans and POST
.../plans/{id}/execute. The frontend adds an 08/REBALANCE panel with
target editing (two codes, sum must equal 100), a plan list with a
manual execute button and post-run outcome rows; executing refreshes
orders/positions so the new orders are immediately visible. Domain
tests cover split validation, diff orders, exit/clamp logic, key
determinism; API tests cover create/execute end-to-end; Web tests
cover decoding and stale-execution protection.

1 files changed, 86 insertions, 0 deletions

diff --git a/tests/FundLab.Web.Tests/BoundaryTests.fs b/tests/FundLab.Web.Tests/BoundaryTests.fs
index 5ab327d..2435f32 100644
--- a/tests/FundLab.Web.Tests/BoundaryTests.fs
+++ b/tests/FundLab.Web.Tests/BoundaryTests.fs
@@ -803,3 +803,89 @@ module SipBoundaryTests =
         let staleList, _ = update (SipPlansReadCompleted(1, [| sampleSipRaw () |])) { model with sipReadSeq = 2 }
 
         Assert.Equal(1, staleList.sipPlans.Length)
+
+module RebalanceBoundaryTests =
+
+    open Xunit
+
+    let sampleFundInfo () : FundSummary =
+        {
+            id = "3fa85f64-5717-4562-b3fc-2c963f66afa6"
+            name = "再平衡测试"
+            currency = "CNY"
+            initialCash = "20000.00"
+            initialUnitNav = "1.00000000"
+            isSynthetic = false
+            availableCash = "19500.00"
+            reservedCash = "0.00"
+            status = "active"
+        }
+
+    let sampleRebalanceRaw () : RawRebalancePlan =
+        {
+            id = "bb2c3d4e-0000-0000-0000-000000000003"
+            fundId = "3fa85f64-5717-4562-b3fc-2c963f66afa6"
+            targets =
+                [|
+                    { instrumentCode = "000001"; targetPercent = "60.00" }
+                    { instrumentCode = "000002"; targetPercent = "40.00" }
+                |]
+            status = "active"
+            createdAt = "2026-09-21T10:00:00+00:00"
+        }
+
+    let sampleExecutionRaw () : RawRebalanceExecution =
+        {
+            planId = "cc3d4e5f-0000-0000-0000-000000000004"
+            runDate = "2026-09-21"
+            outcomes =
+                [|
+                    {
+                        instrumentCode = "000002"
+                        action = "buy"
+                        amount = "4800.00"
+                        status = "succeeded"
+                        orderId = box "9d8c7b6a-0000-0000-0000-000000000009"
+                        pendingReason = null
+                    }
+                |]
+        }
+
+    [<Fact>]
+    let ``rebalance decode keeps decimal strings per target`` () =
+        let decoded = Api.decodeRebalancePlan (sampleRebalanceRaw ())
+
+        Assert.Equal(2, decoded.targets.Length)
+        Assert.Equal("000001", decoded.targets[0].instrumentCode)
+        Assert.Equal("60.00", decoded.targets[0].targetPercent)
+        Assert.Equal("40.00", decoded.targets[1].targetPercent)
+        Assert.Equal("active", decoded.status)
+
+    [<Fact>]
+    let ``rebalance execution decodes outcome fields and refreshes orders`` () =
+        let started, _ =
+            update (RebalanceExecuteRequested "cc3d4e5f-0000-0000-0000-000000000004")
+                { init () with token = "qa-token"; createdFund = Some(sampleFundInfo ()); rebalExecuteSeq = 0 }
+
+        Assert.Equal(1, started.rebalExecuteSeq)
+        Assert.True(started.rebalExecuteInFlight)
+
+        let executed, _ = update (RebalanceExecuted(1, sampleExecutionRaw ())) started
+
+        Assert.False(executed.rebalExecuteInFlight)
+        let result = executed.rebalResult.Value
+        Assert.Equal(1, result.Length)
+        Assert.Equal("buy", result[0].action)
+        Assert.Equal("4800.00", result[0].amount)
+        Assert.Equal("9d8c7b6a-0000-0000-0000-000000000009", result[0].orderId.Value)
+        Assert.Equal(None, result[0].pendingReason)
+
+    [<Fact>]
+    let ``stale rebalance executions are ignored`` () =
+        let model =
+            { init () with token = "qa-token"; createdFund = Some(sampleFundInfo ()); rebalExecuteSeq = 3; rebalExecuteInFlight = true }
+
+        let stale, _ = update (RebalanceExecuted(2, sampleExecutionRaw ())) model
+
+        Assert.True(stale.rebalExecuteInFlight)
+        Assert.Equal(None, stale.rebalResult)