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/Views/CompanySettings/Index.cshtml

@@ -106,11 +106,14 @@
                 <i class="bi bi-tablet"></i> Kiosk
             </button>
         </li>
+        @if (ViewBag.AllowCustomFormulas == true)
+        {
         <li class="nav-item" role="presentation">
             <button class="nav-link" id="custom-formulas-tab" data-bs-toggle="tab" data-bs-target="#custom-formulas" type="button" role="tab">
                 <i class="bi bi-calculator"></i> Custom Formulas
             </button>
         </li>
+        }
     </ul>
 
     <!-- Tabs Content -->
@@ -2060,6 +2063,8 @@
         </div>
 
         <!-- ── Custom Formula Item Templates ──────────────────────────────── -->
+        @if (ViewBag.AllowCustomFormulas == true)
+        {
         <div class="tab-pane fade" id="custom-formulas" role="tabpanel">
             <div class="card shadow-sm mt-3">
                 <div class="card-header d-flex justify-content-between align-items-center">
@@ -2098,6 +2103,7 @@
                 </div>
             </div>
         </div>
+        }
 
     </div>
 </div>
@@ -2172,7 +2178,7 @@
                             <label class="form-label">Formula <span class="text-danger">*</span></label>
                             <input type="text" id="cfFormula" class="form-control font-monospace" placeholder="e.g. 2*(L*W + L*H + W*H)/144 * rate" />
                             <div class="form-text mt-1">
-                                <span class="me-1">Available variables for this formula:</span>
+                                <span class="me-1">Variables (click to insert):</span>
                                 <span id="cfVariablePills"></span>
                             </div>
                         </div>