Add additional capital deposit flow (3d-4)

Deposits credit a fund's available cash directly: Domain gains
CapitalPolicy (positive, two-decimal, overflow-checked amounts plus a
settle function that never touches units, NAV or realized P&L).
Persistence records deposits in fund_capital_deposits with a
fund_capital_idempotencies table, crediting cash and the deposit row
atomically under the same replay/conflict semantics as orders. The
API exposes POST /funds/{id}/capital/deposit and GET
/funds/{id}/capital/deposits behind the bearer token and idempotency
keys. The frontend adds an '追加资金' entry on the fund cash card with
in-place balance refresh, and repeats of the same amount reuse the
idempotency key so double submits credit cash exactly once. Browser
QA extends the J-series (J12-J18): invalid-amount rejection without
POST, single credited deposit with a 32-hex key, instant balance
refresh, unchanged units/cost proving no realized-income impact, and
same-key replay crediting only once.

1 files changed, 89 insertions, 0 deletions

diff --git a/src/FundLab.Api/App.fs b/src/FundLab.Api/App.fs
index 9712fc6..55a29f4 100644
--- a/src/FundLab.Api/App.fs
+++ b/src/FundLab.Api/App.fs
@@ -131,6 +131,16 @@ type FundPositionsResponse =
         positions: FundPositionResponse list
     }
 
+type CapitalDepositResponse =
+    {
+        id: Guid
+        fundId: Guid
+        amount: string
+        note: string option
+        isSynthetic: bool
+        createdAt: string
+    }
+
 type ApiErrorResponse =
     {
         error: string
@@ -261,6 +271,16 @@ module App =
             isSynthetic = order.IsSynthetic
         }
 
+    let private capitalDepositResponse (deposit: CapitalDepositRecord) : CapitalDepositResponse =
+        {
+            id = deposit.Id
+            fundId = deposit.FundId
+            amount = cashText deposit.Amount
+            note = deposit.Note
+            isSynthetic = deposit.IsSynthetic
+            createdAt = timestampText deposit.CreatedAt
+        }
+
     let private errorResponse status error message : HttpHandler =
         setStatusCode status
         >=> json ({
@@ -369,6 +389,28 @@ module App =
         with
         | :? JsonException -> Error "request body must be valid JSON"
 
+    let private parseCapitalDepositCommand (body: string) =
+        try
+            use document = JsonDocument.Parse(body)
+            let root = document.RootElement
+
+            if root.ValueKind <> JsonValueKind.Object then
+                Error "request body must be a JSON object"
+            else
+                match tryStringProperty root "amount" with
+                | None -> Error "amount is required"
+                | Some amountText ->
+                    match tryDecimal "amount" amountText with
+                    | Error message -> Error message
+                    | Ok amount ->
+                        Ok
+                            {
+                                Amount = amount
+                                Note = tryStringProperty root "note"
+                            }
+        with
+        | :? JsonException -> Error "request body must be valid JSON"
+
     let private invokeHandler handler next ctx = handler next ctx
 
     let private unauthorized : HttpHandler =
@@ -621,6 +663,51 @@ module App =
                 with _ ->
                     errorResponse 500 "PERSISTENCE_ERROR" "redemption confirmation failed" next ctx
 
+
+    let private createCapitalDeposit (repository: FundRepository) (fundIdText: string) : HttpHandler =
+        fun next ctx ->
+            task {
+                match Guid.TryParse fundIdText with
+                | false, _ ->
+                    return! invokeHandler (errorResponse 400 "INVALID_CAPITAL_REQUEST" "fund id must be a UUID") next ctx
+                | true, fundId ->
+                    use reader = new StreamReader(ctx.Request.Body)
+                    let! body = reader.ReadToEndAsync()
+                    let idempotencyKey = ctx.Request.Headers["Idempotency-Key"].ToString()
+
+                    match parseCapitalDepositCommand body with
+                    | Error message ->
+                        return! invokeHandler (errorResponse 400 "INVALID_CAPITAL_REQUEST" message) next ctx
+                    | Ok command ->
+                        try
+                            match repository.CreateCapitalDeposit(idempotencyKey, fundId, command) with
+                            | CapitalDepositWriteResult.CapitalDepositCreated deposit ->
+                                return! invokeHandler (setStatusCode 201 >=> json (capitalDepositResponse deposit)) next ctx
+                            | CapitalDepositWriteResult.CapitalDepositReplayed deposit ->
+                                return! invokeHandler (json (capitalDepositResponse deposit)) next ctx
+                            | CapitalDepositWriteResult.CapitalDepositIdempotencyConflict ->
+                                return! invokeHandler (errorResponse 409 "IDEMPOTENCY_CONFLICT" "idempotency key was used with a different request") next ctx
+                            | CapitalDepositWriteResult.CapitalDepositInvalid message ->
+                                return! invokeHandler (errorResponse 400 "INVALID_CAPITAL_REQUEST" message) next ctx
+                            | CapitalDepositWriteResult.CapitalDepositFundNotFound ->
+                                return! invokeHandler (errorResponse 404 "FUND_NOT_FOUND" "fund was not found") next ctx
+                        with _ ->
+                            return! invokeHandler (errorResponse 500 "PERSISTENCE_ERROR" "capital deposit persistence failed") next ctx
+            }
+
+    let private getCapitalDeposits (repository: FundRepository) (fundIdText: string) : HttpHandler =
+        fun next ctx ->
+            match Guid.TryParse fundIdText with
+            | false, _ -> errorResponse 400 "INVALID_FUND_ID" "fund id must be a UUID" next ctx
+            | true, fundId ->
+                try
+                    match repository.GetFund fundId with
+                    | None -> errorResponse 404 "FUND_NOT_FOUND" "fund was not found" next ctx
+                    | Some _ ->
+                        let deposits = repository.GetCapitalDeposits fundId
+                        json (deposits |> List.map capitalDepositResponse) next ctx
+                with _ ->
+                    errorResponse 500 "PERSISTENCE_ERROR" "capital deposit persistence failed" next ctx
     let private marketDataError (failure: MarketDataFailure) : HttpHandler =
         let status, error, message =
             match failure with
@@ -723,6 +810,8 @@ module App =
                 GET >=> routef "/funds/%s/redemptions" (getRedemptions repository)
                 POST >=> routef "/funds/%s/redemptions/%s/confirm" (fun (fundId, orderId) -> confirmRedemption repository fundId orderId)
                 GET >=> routef "/funds/%s/positions" (getPositions repository)
+                POST >=> routef "/funds/%s/capital/deposit" (createCapitalDeposit repository)
+                GET >=> routef "/funds/%s/capital/deposits" (getCapitalDeposits repository)
                 GET >=> routef "/funds/%s" (getFund repository)
             ]
             @ (marketData |> Option.map marketDataRoutes |> Option.defaultValue [])