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Interfaces/Services/IProfitLossService.cs

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+using Fitness_core_BE.DTOs.Ledger;
+using Microsoft.AspNetCore.Http;
+
+namespace Fitness_core_BE.Interfaces.Services
+{
+    // Basic P&L / ledger for the client portal. Derives income (approved member payments)
+    // and expenses (platform fees paid, staff payroll) from existing tables, and merges in
+    // manual ledger entries (LedgerEntry) for anything else (rent, utilities, misc income).
+    public interface IProfitLossService
+    {
+        Task<ProfitLossDto> GetProfitLossAsync(DateTime from, DateTime to, HttpContext httpContext);
+        Task<List<LedgerEntryDto>> GetManualEntriesAsync(DateTime from, DateTime to, HttpContext httpContext);
+        Task<LedgerEntryDto> AddManualEntryAsync(AddLedgerEntryRequest request, HttpContext httpContext);
+        Task DeleteManualEntryAsync(Guid id, HttpContext httpContext);
+    }
+}