Add Custom Powder Order line item and fix CSV import FinalPrice crash

Custom powder/incoming powder material cost now flows into a separate
auto-generated 'Custom Powder Order' line item instead of rolling into
individual item prices, so users can add shipping charges before the
customer sees the total. A dashed yellow preview card in the wizard
shows the material cost and lets users edit the total (including shipping)
before saving. After first save the price is user-owned.

Also fixes a fatal CSV import crash when FinalPrice contains a non-numeric
value (e.g. 'false' from a spreadsheet formula): the job CSV importer now
streams rows one at a time with a lenient decimal converter, treating bad
values as $0 with a per-row warning instead of aborting the entire import.

Updated HelpKnowledgeBase.cs and Help articles (Jobs, Quotes) with
Custom Powder Order behavior and a new Data Import / Export section.

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

src/PowderCoating.Infrastructure/Services/CsvImportService.cs

@@ -1268,24 +1268,22 @@ public class CsvImportService : ICsvImportService
                 MissingFieldFound = null
             });
 
-            var records = csv.GetRecords<JobImportDto>().ToList();
-            result.TotalRows = records.Count;
+            // Treat non-numeric values in decimal? fields (e.g. a spreadsheet "false" in FinalPrice)
+            // as null rather than throwing a fatal TypeConverterException.
+            csv.Context.TypeConverterCache.AddConverter<decimal?>(new LenientNullableDecimalConverter());
 
-            _logger.LogInformation("Starting import of {Count} jobs for company {CompanyId}", records.Count, companyId);
+            // Read header row first so we know field count before iterating rows.
+            await csv.ReadAsync();
+            csv.ReadHeader();
 
-            // Get all existing jobs for duplicate detection
+            // Pre-load lookup data before streaming rows so async calls don't interleave with CSV reads.
             var existingJobs = await _unitOfWork.Jobs.GetAllAsync();
             var existingJobNumbers = existingJobs.Where(j => !string.IsNullOrEmpty(j.JobNumber))
                 .ToDictionary(j => j.JobNumber.ToUpper(), j => j, StringComparer.OrdinalIgnoreCase);
 
-            // Get customers for lookup — build two dictionaries so we can resolve by email
-            // first and fall back to company name when the customer has no email on file.
             var customers = await _unitOfWork.Customers.GetAllAsync();
             var customerByEmail = customers.Where(c => !string.IsNullOrEmpty(c.Email))
                 .ToDictionary(c => c.Email!.Trim().ToLower(), c => c, StringComparer.OrdinalIgnoreCase);
-            // Name fallback: keyed on CompanyName (commercial) or "First Last" (non-commercial).
-            // TryAdd ensures that if two customers share the same name the first one wins and the
-            // lookup warning will prompt the user to resolve the ambiguity manually.
             var customerByName = new Dictionary<string, Customer>(StringComparer.OrdinalIgnoreCase);
             foreach (var c in customers)
             {
@@ -1296,19 +1294,42 @@ public class CsvImportService : ICsvImportService
                     customerByName.TryAdd(name, c);
             }
 
-            // Get job statuses for lookup
             var jobStatuses = await _unitOfWork.JobStatusLookups.GetAllAsync();
             var jobStatusDict = jobStatuses.ToDictionary(js => js.StatusCode.ToUpper(), js => js, StringComparer.OrdinalIgnoreCase);
 
-            // Get job priorities for lookup
             var jobPriorities = await _unitOfWork.JobPriorityLookups.GetAllAsync();
             var jobPriorityDict = jobPriorities.ToDictionary(jp => jp.PriorityCode.ToUpper(), jp => jp, StringComparer.OrdinalIgnoreCase);
 
             var jobsToImport = new List<(int RowNumber, Job Job, string JobNumber)>();
 
-            foreach (var record in records)
+            // Stream rows one at a time so a bad type conversion on a single row (e.g. "false"
+            // in a decimal field) is caught per-row rather than aborting the entire import.
+            while (await csv.ReadAsync())
             {
-                rowNumber++;
+                result.TotalRows++;
+                JobImportDto record;
+                try
+                {
+                    record = csv.GetRecord<JobImportDto>()
+                        ?? throw new InvalidOperationException("Row returned null record.");
+                }
+                catch (Exception parseEx)
+                {
+                    result.Errors.Add($"Row {csv.Context.Parser?.Row}: Could not parse row - {parseEx.InnerException?.Message ?? parseEx.Message}");
+                    result.ErrorCount++;
+                    _logger.LogWarning(parseEx, "Parse error at CSV row {Row}", csv.Context.Parser?.Row);
+                    continue;
+                }
+
+                rowNumber = csv.Context.Parser?.Row ?? rowNumber + 1;
+
+                // Warn when FinalPrice was non-numeric (lenient converter returned null).
+                var rawFinalPrice = csv.TryGetField<string>(7, out var fpStr) ? fpStr : null;
+                if (!string.IsNullOrWhiteSpace(rawFinalPrice) && record.FinalPrice == null
+                    && !decimal.TryParse(rawFinalPrice, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out _))
+                {
+                    result.Warnings.Add($"Row {rowNumber}: FinalPrice value '{rawFinalPrice}' could not be parsed as a number; defaulting to $0.");
+                }
                 try
                 {
                     // Validate required fields
@@ -3340,4 +3361,23 @@ public class CsvImportService : ICsvImportService
             return result;
         }
     }
+
+    /// <summary>
+    /// Returns null for any value that cannot be parsed as a decimal, instead of throwing a
+    /// TypeConverterException. Registered globally on the job CSV reader so that spreadsheet
+    /// artefacts like "false" in a price column are treated as $0 with a warning.
+    /// </summary>
+    private sealed class LenientNullableDecimalConverter : CsvHelper.TypeConversion.ITypeConverter
+    {
+        public object? ConvertFromString(string? text, CsvHelper.IReaderRow row, CsvHelper.Configuration.MemberMapData memberMapData)
+        {
+            if (string.IsNullOrWhiteSpace(text)) return null;
+            return decimal.TryParse(text, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out var v)
+                ? (object?)v
+                : null;
+        }
+
+        public string? ConvertToString(object? value, CsvHelper.IWriterRow row, CsvHelper.Configuration.MemberMapData memberMapData)
+            => value?.ToString();
+    }
 }