Phase C: Add Manual Journal Entries (double-entry GL)

- JournalEntry + JournalEntryLine entities with Draft/Posted/Reversed lifecycle
- JournalEntryStatus enum (Draft, Posted, Reversed)
- Migration AddJournalEntries: two new tables with self-referencing reversal FK
- IUnitOfWork/UnitOfWork wired with JournalEntries + JournalEntryLines repos
- ApplicationDbContext: DbSets, tenant query filters, reversal FK config
- LedgerService: JE lines added as 10th source in GetAccountLedgerAsync and ComputePriorBalanceAsync
- JournalEntriesController: Index (All/Draft/Posted tabs), Create, Details, Post, Reverse, Delete
- Views: Index, Create (dynamic balanced line grid with running debit/credit totals), Details
- journal-entry-create.js: dynamic line management with balance indicator
- Nav: Journal Entries added to Finance section in _Layout

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Infrastructure/Services/LedgerService.cs

@@ -298,6 +298,28 @@ public class LedgerService : ILedgerService
                 });
         }
 
+        // ── 10. Journal Entry lines touching this account ──────────────────
+        var jeLines = await _context.JournalEntryLines
+            .Include(l => l.JournalEntry)
+            .Where(l => l.AccountId == accountId
+                     && l.JournalEntry.Status == JournalEntryStatus.Posted
+                     && l.JournalEntry.EntryDate >= fromDate
+                     && l.JournalEntry.EntryDate <= toDate)
+            .ToListAsync();
+
+        foreach (var line in jeLines)
+            entries.Add(new LedgerEntryDto
+            {
+                Date = line.JournalEntry.EntryDate,
+                Reference = line.JournalEntry.EntryNumber,
+                Source = "Journal Entry",
+                Description = line.Description ?? line.JournalEntry.Description,
+                Debit = line.DebitAmount,
+                Credit = line.CreditAmount,
+                LinkController = "JournalEntries",
+                LinkId = line.JournalEntry.Id
+            });
+
         // ── Sort and compute running balance ──────────────────────────────────
         entries = entries
             .OrderBy(e => e.Date)
@@ -429,6 +451,19 @@ public class LedgerService : ILedgerService
                 .SumAsync(bp => (decimal?)bp.Amount) ?? 0;
         }
 
+        // 10. Posted journal entry lines touching this account (prior to period)
+        debits += await _context.JournalEntryLines
+            .Where(l => l.AccountId == accountId
+                     && l.JournalEntry.Status == JournalEntryStatus.Posted
+                     && l.JournalEntry.EntryDate < beforeDate)
+            .SumAsync(l => (decimal?)l.DebitAmount) ?? 0;
+
+        credits += await _context.JournalEntryLines
+            .Where(l => l.AccountId == accountId
+                     && l.JournalEntry.Status == JournalEntryStatus.Posted
+                     && l.JournalEntry.EntryDate < beforeDate)
+            .SumAsync(l => (decimal?)l.CreditAmount) ?? 0;
+
         decimal netActivity = normalDebitBalance ? debits - credits : credits - debits;
 
         // Apply the opening balance if it was established on or before the end of the viewed period.