Add Employee Timeclock feature with kiosk, attendance report, and payroll CSV export

- New EmployeeClockEntry entity (facility-level attendance, separate from job time entries)
- KioskPin added to ApplicationUser; TimeclockKioskToken added to Company
- TimeclockController: clock in/out, who's in, 14-day history, manager edit/delete,
  tablet kiosk with device-cookie auth, PIN management via Users edit page
- Kiosk UI: employee tile grid + 4-digit PIN pad + auto-detect clock-in vs clock-out
- Attendance report at /Reports/Attendance with weekly subtotal rows
- Payroll CSV export at /Reports/AttendanceCsv (flat, one row per segment)
- AllowCustomFormulas wired through PlatformSubscriptionController + subscription views
- Fix soft-delete bug on CustomItemTemplate (missing HasQueryFilter in OnModelCreating)
- Help article (Help/Timeclock.cshtml) and AI knowledge base updated
- Migrations: AddEmployeeTimeclock, AddTimeclockKioskToken

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

src/PowderCoating.Web/Controllers/PlatformSubscriptionController.cs

@@ -65,6 +65,7 @@ public class PlatformSubscriptionController : Controller
             AllowAiInventoryAssist = c.AllowAiInventoryAssist,
             AllowAiCatalogPriceCheck = c.AllowAiCatalogPriceCheck,
             AllowSms = c.AllowSms,
+            AllowCustomFormulas = c.AllowCustomFormulas,
             IsActive = c.IsActive,
             SortOrder = c.SortOrder
         }).ToList();
@@ -106,6 +107,7 @@ public class PlatformSubscriptionController : Controller
             AllowAiInventoryAssist = config.AllowAiInventoryAssist,
             AllowAiCatalogPriceCheck = config.AllowAiCatalogPriceCheck,
             AllowSms = config.AllowSms,
+            AllowCustomFormulas = config.AllowCustomFormulas,
             IsActive = config.IsActive
         };
 
@@ -152,6 +154,7 @@ public class PlatformSubscriptionController : Controller
         config.AllowAiInventoryAssist = dto.AllowAiInventoryAssist;
         config.AllowAiCatalogPriceCheck = dto.AllowAiCatalogPriceCheck;
         config.AllowSms = dto.AllowSms;
+        config.AllowCustomFormulas = dto.AllowCustomFormulas;
         config.IsActive = dto.IsActive;
 
         await _unitOfWork.SubscriptionPlanConfigs.UpdateAsync(config);