Add manual Log Material modal to job details page

PC users were blocked to QR scan only for logging material usage. Now a
"Log Material" button opens an inline modal with:
- Inventory item dropdown (name + unit of measure, current stock shown on select)
- Entry method toggle: "Amount Used" or "Amount Remaining" (computes used = onHand - remaining)
- Reason: Job Usage or Waste/Spillage
- Notes field
Submits via AJAX to Jobs/LogMaterial (new POST action) which mirrors the
InventoryController.LogUsage flow — updates QuantityOnHand, creates InventoryTransaction,
posts GL entries (DR COGS / CR Inventory). QR scan button retained as icon.

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

src/PowderCoating.Web/Controllers/JobsController.cs

@@ -498,6 +498,13 @@ public class JobsController : Controller
                 .OrderByDescending(t => t.TransactionDate).ToList();
             ViewBag.MaterialsUsed = allJobTransactions;
 
+            // Inventory items for the manual log-material modal
+            var inventoryItemsForModal = (await _unitOfWork.InventoryItems.GetAllAsync())
+                .OrderBy(i => i.Name)
+                .Select(i => new { i.Id, i.Name, i.UnitOfMeasure, i.QuantityOnHand })
+                .ToList();
+            ViewBag.InventoryItemsForModal = System.Text.Json.JsonSerializer.Serialize(inventoryItemsForModal);
+
             // Pre-logged powder grouped by InventoryItemId (for Complete Job modal pre-fill)
             ViewBag.PreLoggedPowder = allJobTransactions
                 .GroupBy(t => t.InventoryItemId)
@@ -4080,9 +4087,87 @@ public class JobsController : Controller
 
         _logger.LogInformation("Recorded first job creation for company {CompanyId}", companyId);
     }
+
+    /// <summary>
+    /// Logs manual material usage from the job details page. Mirrors the QR scan LogUsage
+    /// flow in InventoryController but returns JSON so the modal can close and refresh inline.
+    /// Quantity is always the amount USED (caller converts from remaining if needed).
+    /// </summary>
+    [HttpPost]
+    [ValidateAntiForgeryToken]
+    public async Task<IActionResult> LogMaterial([FromBody] LogMaterialRequest req)
+    {
+        try
+        {
+            if (req.QuantityUsed <= 0)
+                return Json(new { success = false, message = "Quantity used must be greater than zero." });
+
+            var item = await _unitOfWork.InventoryItems.GetByIdAsync(req.InventoryItemId);
+            if (item == null) return Json(new { success = false, message = "Inventory item not found." });
+
+            var job = await _unitOfWork.Jobs.GetByIdAsync(req.JobId);
+            if (job == null) return Json(new { success = false, message = "Job not found." });
+
+            var txnType = req.TransactionType == "Waste"
+                ? InventoryTransactionType.Waste
+                : InventoryTransactionType.JobUsage;
+
+            item.QuantityOnHand -= req.QuantityUsed;
+            item.UpdatedAt = DateTime.UtcNow;
+            await _unitOfWork.InventoryItems.UpdateAsync(item);
+
+            var txn = new PowderCoating.Core.Entities.InventoryTransaction
+            {
+                InventoryItemId = item.Id,
+                TransactionType = txnType,
+                Quantity        = -req.QuantityUsed,
+                UnitCost        = item.UnitCost,
+                TotalCost       = req.QuantityUsed * item.UnitCost,
+                TransactionDate = DateTime.UtcNow,
+                BalanceAfter    = item.QuantityOnHand,
+                JobId           = req.JobId,
+                Reference       = $"Job {job.JobNumber}",
+                Notes           = req.Notes?.Trim(),
+                CompanyId       = item.CompanyId,
+                CreatedAt       = DateTime.UtcNow
+            };
+            await _unitOfWork.InventoryTransactions.AddAsync(txn);
+            await _unitOfWork.CompleteAsync();
+
+            // GL: DR COGS, CR Inventory Asset
+            if (item.CogsAccountId.HasValue && item.InventoryAccountId.HasValue)
+            {
+                var cost = req.QuantityUsed * (item.AverageCost > 0 ? item.AverageCost : item.UnitCost);
+                await _accountBalanceService.DebitAsync(item.CogsAccountId, cost);
+                await _accountBalanceService.CreditAsync(item.InventoryAccountId, cost);
+            }
+
+            return Json(new
+            {
+                success    = true,
+                message    = $"Logged {req.QuantityUsed:N2} {item.UnitOfMeasure} of {item.Name}.",
+                newBalance = item.QuantityOnHand,
+                unitOfMeasure = item.UnitOfMeasure,
+                itemName   = item.Name
+            });
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error logging material for job {JobId}", req.JobId);
+            return Json(new { success = false, message = "An error occurred. Please try again." });
+        }
+    }
 }
 
 public class DeleteTimeEntryRequest { public int Id { get; set; } }
+public class LogMaterialRequest
+{
+    public int     JobId           { get; set; }
+    public int     InventoryItemId { get; set; }
+    public decimal QuantityUsed    { get; set; }
+    public string  TransactionType { get; set; } = "JobUsage";
+    public string? Notes           { get; set; }
+}
 public class CreateReworkJobRequest { public int ReworkRecordId { get; set; } public string? Notes { get; set; } }
 
 public class UpdateWorkerAssignmentRequest