Phase 2: Eliminate ApplicationDbContext from domain controllers

Migrated InvoicesController, QuotesController, JobsController, BillsController,
PurchaseOrdersController, and CustomersController to route all data access
through IUnitOfWork typed/generic repositories instead of injecting
ApplicationDbContext directly.

New typed repositories added: IJobRepository (GetScheduledJobsForDateAsync,
GetActiveJobsForMobileAsync, LoadForCostingAsync), INotificationLogRepository
(GetLatestForJobAsync, GetAllForJobAsync), IQuoteRepository (GetItemsWithCoatsAsync
with CatalogItem eager load + AsNoTracking), and IJobRepository.GetOrphanedConversionJobAsync.

All EF complex include chains relocated into repository methods; controllers now
call named query methods rather than composing raw IQueryable chains.

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

src/PowderCoating.Infrastructure/Repositories/BillRepository.cs

@@ -1,5 +1,6 @@
 using Microsoft.EntityFrameworkCore;
 using PowderCoating.Core.Entities;
+using PowderCoating.Core.Enums;
 using PowderCoating.Core.Interfaces.Repositories;
 using PowderCoating.Infrastructure.Data;
 
@@ -37,4 +38,55 @@ public class BillRepository : Repository<Bill>, IBillRepository
             .Include(b => b.LineItems.Where(li => !li.IsDeleted))
             .FirstOrDefaultAsync();
     }
+
+    /// <inheritdoc/>
+    public async Task<List<Bill>> GetForIndexAsync(string? statusFilter, string? searchTerm, decimal? searchAmount)
+    {
+        var query = _context.Bills
+            .Include(b => b.Vendor)
+            .Include(b => b.LineItems.Where(li => !li.IsDeleted))
+            .Where(b => !b.IsDeleted);
+
+        if (statusFilter == "Unpaid")
+            query = query.Where(b => b.Status == BillStatus.Open || b.Status == BillStatus.PartiallyPaid);
+        else if (statusFilter == "Overdue")
+            query = query.Where(b => b.Status != BillStatus.Paid && b.Status != BillStatus.Voided &&
+                                     b.DueDate.HasValue && b.DueDate.Value.Date < DateTime.Today);
+
+        if (!string.IsNullOrEmpty(searchTerm))
+        {
+            var term = searchTerm;
+            query = query.Where(b =>
+                b.BillNumber.Contains(term) ||
+                b.Vendor.CompanyName.Contains(term) ||
+                (b.VendorInvoiceNumber != null && b.VendorInvoiceNumber.Contains(term)) ||
+                (b.Memo != null && b.Memo.Contains(term)) ||
+                b.LineItems.Any(li => li.Description.Contains(term)) ||
+                (searchAmount.HasValue && (b.Total == searchAmount.Value || b.AmountPaid == searchAmount.Value)));
+        }
+
+        return await query.OrderByDescending(b => b.BillDate).ToListAsync();
+    }
+
+    /// <inheritdoc/>
+    public async Task<string?> GetLastBillNumberAsync(string prefix)
+    {
+        return await _context.Bills
+            .IgnoreQueryFilters()
+            .Where(b => b.BillNumber.StartsWith(prefix))
+            .OrderByDescending(b => b.BillNumber)
+            .Select(b => b.BillNumber)
+            .FirstOrDefaultAsync();
+    }
+
+    /// <inheritdoc/>
+    public async Task<string?> GetLastPaymentNumberAsync(string prefix)
+    {
+        return await _context.BillPayments
+            .IgnoreQueryFilters()
+            .Where(p => p.PaymentNumber.StartsWith(prefix))
+            .OrderByDescending(p => p.PaymentNumber)
+            .Select(p => p.PaymentNumber)
+            .FirstOrDefaultAsync();
+    }
 }