Enhance financial report accuracy by including closing journals in profit and loss calculations and trial balances; add idempotency check for journal entry creation.

Services/ReportService.cs

@@ -189,8 +189,13 @@ namespace General_Ledger_Service.Services
             // project owner 2026-07-20 - see CLAUDE.md/03_Progress_Tracker.md. Folded into the
             // Equity section as its own line (retrofit 2026-07-31) rather than a separate
             // top-level field, since it's conceptually an Equity line item.
-            var profitAndLoss = await BuildProfitAndLossReportAsync(DateOnly.MinValue, asOfDate);
-            equity.Lines.Add(new BalanceSheetLineDto { AccountCode = "", AccountName = "Current Year Earnings", Balance = profitAndLoss.NetProfitForPeriod });
+            var profitAndLoss = await BuildProfitAndLossReportAsync(DateOnly.MinValue, asOfDate, includeClosing: true);
+
+            // Equity shows the real equity accounts plus ONE calculated line: the profit of the period not yet
+            // closed into Retained Earnings. Closing journals are included above, so once a year is closed its
+            // profit sits in Retained Earnings and this line only carries the open period. The income/expense
+            // detail belongs to the ProfitAndLoss report, not the balance sheet.
+            equity.Lines.Add(new BalanceSheetLineDto { AccountCode = "", AccountName = "Current Year Profit", Balance = profitAndLoss.NetProfitForPeriod });
             equity.Total += profitAndLoss.NetProfitForPeriod;
 
             var totalAssets = nonCurrentAssets.Total + currentAssets.Total + unclassifiedAssets.Total;
@@ -223,9 +228,9 @@ namespace General_Ledger_Service.Services
         // profitForPeriod - all three just need the resulting NetProfitForPeriod figure, computed
         // once here from the raw leaf rows so the Expense-side sign convention lives in exactly
         // one place.
-        private async Task<ProfitAndLossReportDto> BuildProfitAndLossReportAsync(DateOnly periodStart, DateOnly periodEnd)
+        private async Task<ProfitAndLossReportDto> BuildProfitAndLossReportAsync(DateOnly periodStart, DateOnly periodEnd, bool includeClosing = false)
         {
-            var leafRows = await _accountRepository.GetProfitAndLossLeafRowsAsync(periodStart, periodEnd);
+            var leafRows = await _accountRepository.GetProfitAndLossLeafRowsAsync(periodStart, periodEnd, includeClosing);
 
             // Raw Amount (credit - debit) is already positive-normal for Income (account_type_id
             // 4) but negative-normal for Expense (account_type_id 5, debit-normal) - flip Expense