Refactor: extract shared helpers, fix field drift, add assembly services

- IJobItemAssemblyService / IQuotePricingAssemblyService: centralize job item
  and quote pricing construction that was duplicated across create, rework copy,
  and quote-to-job conversion paths
- BlobFileHelper: single ValidateUpload/GetContentType/SanitizeFileName used by
  6 blob services (JobPhoto, QuotePhoto, ProfilePhoto, CompanyLogo, Equipment,
  Catalog) and BillsController + ExpensesController, removing 8 private copies
- PagedResult<T>.From(): static factory eliminates 6-line boilerplate in 11
  controllers (Appointments, Customers, Equipment, Inventory, Invoices, Jobs,
  Maintenance, CompanyUsers, PlatformUsers, Quotes, Vendors)
- AccountingDropdownHelper: single LoadAsync() call replaces duplicate
  vendor/account/job queries in BillsController and ExpensesController
- JobTemplateItem: add IsSalesItem + Sku fields with migration; propagate
  through JobTemplatesController snapshot copy and GetTemplatesJson projection,
  and JobsController template-application path
- Test assertions updated for standardized BlobFileHelper error messages

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

src/PowderCoating.Web/Controllers/BillsController.cs

@@ -8,6 +8,7 @@ using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Options;
 using PowderCoating.Application.Configuration;
+using PowderCoating.Application.Services;
 using PowderCoating.Application.DTOs.Accounting;
 using PowderCoating.Application.DTOs.AI;
 using PowderCoating.Application.Interfaces;
@@ -15,6 +16,7 @@ using PowderCoating.Core.Entities;
 using PowderCoating.Core.Enums;
 using PowderCoating.Core.Interfaces;
 using PowderCoating.Application.DTOs.PurchaseOrder;
+using PowderCoating.Web.Helpers;
 
 namespace PowderCoating.Web.Controllers;
 
@@ -345,10 +347,11 @@ public class BillsController : Controller
             // Attach receipt file if provided
             if (receiptFile != null && receiptFile.Length > 0)
             {
-                if (IsValidReceiptFile(receiptFile, out var fileError))
+                var (receiptValid, _, receiptError) = BlobFileHelper.ValidateUpload(receiptFile, AllowedReceiptTypes, MaxReceiptBytes);
+                if (receiptValid)
                     bill.ReceiptFilePath = await UploadReceiptAsync(receiptFile, bill.Id, currentUser.CompanyId);
                 else
-                    TempData["Warning"] = $"Bill saved but receipt not uploaded: {fileError}";
+                    TempData["Warning"] = $"Bill saved but receipt not uploaded: {receiptError}";
                 await _unitOfWork.CompleteAsync();
             }
 
@@ -571,7 +574,8 @@ public class BillsController : Controller
             // Handle receipt file replacement
             if (receiptFile != null && receiptFile.Length > 0)
             {
-                if (IsValidReceiptFile(receiptFile, out var fileError))
+                var (receiptValid, _, receiptError) = BlobFileHelper.ValidateUpload(receiptFile, AllowedReceiptTypes, MaxReceiptBytes);
+                if (receiptValid)
                 {
                     if (!string.IsNullOrEmpty(bill.ReceiptFilePath))
                         await _blobStorage.DeleteAsync(_storageSettings.Containers.ReceiptImages, bill.ReceiptFilePath);
@@ -579,7 +583,7 @@ public class BillsController : Controller
                 }
                 else
                 {
-                    TempData["Warning"] = $"Bill saved but receipt not uploaded: {fileError}";
+                    TempData["Warning"] = $"Bill saved but receipt not uploaded: {receiptError}";
                 }
             }
 
@@ -927,48 +931,13 @@ public class BillsController : Controller
     /// </summary>
     private async Task PopulateDropdownsAsync()
     {
-        var vendors = await _unitOfWork.Vendors.FindAsync(s => s.IsActive);
-        ViewBag.Vendors = vendors
-            .OrderBy(s => s.CompanyName)
-            .Select(s => new SelectListItem(s.CompanyName, s.Id.ToString()))
-            .ToList();
-
-        var allAccounts = await _unitOfWork.Accounts.FindAsync(a => a.IsActive);
-
-        ViewBag.APAccounts = allAccounts
-            .Where(a => a.AccountSubType == AccountSubType.AccountsPayable)
-            .OrderBy(a => a.AccountNumber)
-            .Select(a => new SelectListItem($"{a.AccountNumber} – {a.Name}", a.Id.ToString()))
-            .ToList();
-
-        ViewBag.ExpenseAccounts = allAccounts
-            .Where(a => a.AccountType == AccountType.Expense ||
-                        a.AccountType == AccountType.CostOfGoods ||
-                        a.AccountType == AccountType.Asset)
-            .OrderBy(a => a.AccountNumber)
-            .Select(a => new SelectListItem($"{a.AccountNumber} – {a.Name}", a.Id.ToString()))
-            .ToList();
-
-        ViewBag.BankAccounts = allAccounts
-            .Where(a => a.AccountSubType == AccountSubType.Cash ||
-                        a.AccountSubType == AccountSubType.Checking ||
-                        a.AccountSubType == AccountSubType.Savings ||
-                        a.AccountSubType == AccountSubType.CreditCard)
-            .OrderBy(a => a.AccountNumber)
-            .Select(a => new SelectListItem($"{a.AccountNumber} – {a.Name}", a.Id.ToString()))
-            .ToList();
-
-        ViewBag.PaymentMethods = Enum.GetValues<PaymentMethod>()
-            .Select(m => new SelectListItem(m.ToString(), ((int)m).ToString()))
-            .ToList();
-
-        ViewBag.Jobs = (await _unitOfWork.Jobs.FindAsync(j =>
-                j.JobStatus.StatusCode != "COMPLETED" &&
-                j.JobStatus.StatusCode != "CANCELLED" &&
-                j.JobStatus.StatusCode != "DELIVERED"))
-            .OrderBy(j => j.JobNumber)
-            .Select(j => new SelectListItem($"{j.JobNumber} – {j.Description ?? "No description"}", j.Id.ToString()))
-            .ToList();
+        var dd = await AccountingDropdownHelper.LoadAsync(_unitOfWork);
+        ViewBag.Vendors = dd.Vendors;
+        ViewBag.APAccounts = dd.ApAccounts;
+        ViewBag.ExpenseAccounts = dd.ExpenseAndAssetAccounts;
+        ViewBag.BankAccounts = dd.BankAccounts;
+        ViewBag.PaymentMethods = dd.PaymentMethods;
+        ViewBag.Jobs = dd.ActiveJobs;
     }
 
     /// <summary>
@@ -1023,7 +992,7 @@ public class BillsController : Controller
         if (!result.Success) return NotFound();
 
         var ext = Path.GetExtension(bill.ReceiptFilePath).ToLowerInvariant();
-        var contentType = MimeFromExt(ext);
+        var contentType = BlobFileHelper.GetContentType(ext);
         var fileName = $"receipt-{bill.BillNumber}{ext}";
         return File(result.Content, contentType, fileName);
     }
@@ -1161,41 +1130,8 @@ public class BillsController : Controller
     {
         var ext = Path.GetExtension(file.FileName).ToLowerInvariant();
         var blobName = $"{companyId}/bill-receipts/{billId}/{Guid.NewGuid()}{ext}";
-        var contentType = MimeFromExt(ext);
         using var stream = file.OpenReadStream();
-        var result = await _blobStorage.UploadAsync(_storageSettings.Containers.ReceiptImages, blobName, stream, contentType);
+        var result = await _blobStorage.UploadAsync(_storageSettings.Containers.ReceiptImages, blobName, stream, BlobFileHelper.GetContentType(ext));
         return result.Success ? blobName : null;
     }
-
-    /// <summary>
-    /// Validates a receipt file upload against the allowed extension list and the 10 MB size cap.
-    /// Returns <c>false</c> and populates <paramref name="error"/> with a user-friendly message
-    /// when the file fails either check; returns <c>true</c> and sets <paramref name="error"/> to
-    /// an empty string when the file is acceptable.
-    /// </summary>
-    private static bool IsValidReceiptFile(IFormFile file, out string error)
-    {
-        var ext = Path.GetExtension(file.FileName).ToLowerInvariant();
-        if (!AllowedReceiptTypes.Contains(ext))
-        {
-            error = $"File type '{ext}' is not allowed. Accepted: {string.Join(", ", AllowedReceiptTypes)}";
-            return false;
-        }
-        if (file.Length > MaxReceiptBytes)
-        {
-            error = "Receipt file must be 10 MB or smaller.";
-            return false;
-        }
-        error = string.Empty;
-        return true;
-    }
-
-    private static string MimeFromExt(string ext) => ext switch
-    {
-        ".pdf"  => "application/pdf",
-        ".png"  => "image/png",
-        ".gif"  => "image/gif",
-        ".webp" => "image/webp",
-        _       => "image/jpeg"
-    };
 }