intigrate others sales , return and implement day end duntinalities

Backend/ERPCore/Domain/DocumentTypes.cs

@@ -21,4 +21,7 @@ public static class DocumentTypes
     public const string SalesSlip = "SSL";
     public const string BundleSale = "BND";
     public const string SalesReturn = "SRET";
+
+    /// <summary>Cashier day-end close-out (Sales) — <c>DEND-2026-00001</c>.</summary>
+    public const string SalesDayEnd = "DEND";
 }

Backend/ERPCore/Domain/Entities/BundleSale.cs

@@ -29,5 +29,11 @@ public class BundleSale
     public DateTime? UpdatedAt { get; set; }
     public int ConcurrencyStamp { get; set; }
 
+    /// <summary>Set once this bundle's business date is closed by <see cref="SalesDayEnd"/> — a
+    /// closed bundle sale is frozen (no further edits). Same role as <see cref="SalesSlip.DayEndId"/>;
+    /// a bundle sale is a cashier document exactly like a sales slip, just priced as a set.</summary>
+    public int? DayEndId { get; set; }
+    public SalesDayEnd? DayEnd { get; set; }
+
     public ICollection<BundleSaleLine> Lines { get; set; } = new List<BundleSaleLine>();
 }

Backend/ERPCore/Domain/Entities/PurchaseReturn.cs

@@ -28,5 +28,12 @@ public class PurchaseReturn
 
     public DateTime CreatedAt { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this return (set on create — it auto-posts).
+    /// Reverses the Inventory/Clearing lines a Grn posts — <see cref="PurchaseReturnLine"/> carries no unit
+    /// price/VAT of its own, so it can't reverse a VAT-recoverable line the way a real credit note would.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<PurchaseReturnLine> Lines { get; set; } = new List<PurchaseReturnLine>();
 }
+

Backend/ERPCore/Domain/Entities/SalesDayEnd.cs

@@ -0,0 +1,46 @@
+namespace ERPCore.Domain.Entities;
+
+/// <summary>
+/// A cashier's end-of-day close-out. Aggregates every <see cref="SalesSlip"/> the
+/// cashier posted on <see cref="BusinessDate"/>, freezes them against this record
+/// (<see cref="SalesSlip.DayEndId"/>) so a slip can only ever belong to one day-end,
+/// and posts one consolidated GL journal entry for the day's revenue/tax/COGS —
+/// the sales-side equivalent of how <see cref="Grn"/> posts per receipt. Unique per
+/// (CashierUserId, BusinessDate): closing twice replays the existing record instead
+/// of creating a second one (same idempotent-replay pattern as Grn.ConfirmAsync).
+/// </summary>
+public class SalesDayEnd
+{
+    public int SalesDayEndId { get; set; }
+    public string DocNo { get; set; } = string.Empty;
+
+    public int CashierUserId { get; set; }
+    public User? CashierUser { get; set; }
+
+    /// <summary>The calendar date being closed (matched against each slip's <see cref="SalesSlip.SlipDate"/>, UTC).</summary>
+    public DateOnly BusinessDate { get; set; }
+
+    public int SlipCount { get; set; }
+    public int BundleCount { get; set; }
+    public decimal Subtotal { get; set; }
+    public decimal DiscountTotal { get; set; }
+    public decimal TaxTotal { get; set; }
+    public decimal GrandTotal { get; set; }
+
+    /// <summary>Sum of the FIFO cost consumed for these slips (from <see cref="StockLedger"/>), for the COGS GL lines.</summary>
+    public decimal CostOfGoodsSold { get; set; }
+
+    /// <summary>Journal number of the real GL journal entry posted for this close (null when there was nothing to post).</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
+    public int ClosedBy { get; set; }
+    public User? ClosedByUser { get; set; }
+    public DateTime ClosedAt { get; set; }
+
+    /// <summary>PostgreSQL xmin-backed optimistic concurrency token.</summary>
+    public uint RowVersion { get; set; }
+
+    public ICollection<SalesSlip> Slips { get; set; } = new List<SalesSlip>();
+    public ICollection<BundleSale> BundleSales { get; set; } = new List<BundleSale>();
+}

Backend/ERPCore/Domain/Entities/SalesInvoice.cs

@@ -29,6 +29,14 @@ public class SalesInvoice
     public decimal PaidAmount { get; set; }
     public decimal BalanceAmount { get; set; }
 
+    /// <summary>Journal number of the revenue-recognition GL journal entry posted when this
+    /// invoice is Posted (Debit Accounts Receivable / Credit Sales Revenue + Tax, plus COGS —
+    /// see SalesPostingService.PostInvoiceAsync). Unlike a SalesSlip, an invoice posts its own
+    /// GL entry immediately rather than waiting for Sales Day End, since invoices aren't a
+    /// cashier document and don't go through that close-out.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public int CreatedBy { get; set; }
     public User? Creator { get; set; }
 
@@ -38,4 +46,5 @@ public class SalesInvoice
     public uint RowVersion { get; set; }
 
     public ICollection<SalesInvoiceLine> Lines { get; set; } = new List<SalesInvoiceLine>();
+    public ICollection<SalesInvoicePayment> Payments { get; set; } = new List<SalesInvoicePayment>();
 }

Backend/ERPCore/Domain/Entities/SalesInvoicePayment.cs

@@ -0,0 +1,32 @@
+namespace ERPCore.Domain.Entities;
+
+/// <summary>
+/// A customer payment made against a Posted sales invoice's balance (installments
+/// allowed — see SalesInvoicePaymentService.PayAsync). Posts its own real GL journal
+/// entry (Debit the selected bank-or-cash account / Credit Accounts Receivable) before
+/// being recorded here — the mirror image of <see cref="GrnPayment"/>.
+/// </summary>
+public class SalesInvoicePayment
+{
+    public int SalesInvoicePaymentId { get; set; }
+
+    public int SalesInvoiceId { get; set; }
+    public SalesInvoice? SalesInvoice { get; set; }
+
+    public decimal Amount { get; set; }
+    public DateTime PaymentDate { get; set; }
+
+    /// <summary>GL's numeric id for the bank/cash account the payment was received into.</summary>
+    public long GlBankAccountId { get; set; }
+    /// <summary>Snapshot of the account's display name at payment time (GL account lists have no local FK).</summary>
+    public string BankAccountName { get; set; } = string.Empty;
+
+    public string? Reference { get; set; }
+
+    /// <summary>Journal number of the real GL journal entry this payment posted.</summary>
+    public string? GlJournalNo { get; set; }
+
+    public int CreatedBy { get; set; }
+    public User? Creator { get; set; }
+    public DateTime CreatedAt { get; set; }
+}

Backend/ERPCore/Domain/Entities/SalesReturn.cs

@@ -28,5 +28,11 @@ public class SalesReturn
 
     public DateTime CreatedAt { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this return (set on create — it auto-posts).
+    /// Reverses Inventory/COGS only — <see cref="SalesReturnLine"/> carries no unit price, so revenue/tax aren't
+    /// reversed here (they'd need a per-line price this document doesn't capture).</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<SalesReturnLine> Lines { get; set; } = new List<SalesReturnLine>();
 }

Backend/ERPCore/Domain/Entities/SalesSlip.cs

@@ -27,6 +27,10 @@ public class SalesSlip
     public decimal PaidAmount { get; set; }
     public decimal BalanceAmount { get; set; }
 
+    /// <summary>Set once this slip's business date is closed by <see cref="SalesDayEnd"/> — a closed slip is frozen (no further edits).</summary>
+    public int? DayEndId { get; set; }
+    public SalesDayEnd? DayEnd { get; set; }
+
     public DateTime CreatedAt { get; set; }
     public DateTime? UpdatedAt { get; set; }
 

Backend/ERPCore/Domain/Entities/StockAdjustment.cs

@@ -27,5 +27,10 @@ public class StockAdjustment
     public DateTime CreatedAt { get; set; }
     public uint RowVersion { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this adjustment (set on create — it
+    /// auto-posts). Increases and decreases post separately (never netted) so gains/losses stay visible.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<StockAdjustmentLine> Lines { get; set; } = new List<StockAdjustmentLine>();
 }