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/SubscriptionManagement/Index.cshtml

@@ -97,6 +97,7 @@
                         <tr>
                             <th>Plan</th>
                             <th class="text-center">Online Payments (Stripe Connect)</th>
+                            <th class="text-center">Custom Formula Templates</th>
                         </tr>
                     </thead>
                     <tbody>
@@ -114,12 +115,23 @@
                                                title="Toggle online payment capability for @p.DisplayName plan" />
                                     </div>
                                 </td>
+                                <td class="text-center">
+                                    <div class="form-check form-switch d-inline-block mb-0">
+                                        <input class="form-check-input plan-feature-toggle"
+                                               type="checkbox" role="switch"
+                                               data-plan-id="@p.Id"
+                                               data-feature="AllowCustomFormulas"
+                                               @(p.AllowCustomFormulas ? "checked" : "")
+                                               title="Toggle custom formula templates for @p.DisplayName plan" />
+                                    </div>
+                                </td>
                             </tr>
                         }
                     </tbody>
                 </table>
                 <div class="px-3 py-2 text-muted" style="font-size:0.75rem;">
                     Changes take effect immediately. Companies on a plan with Online Payments enabled can connect their Stripe account in Company Settings.
+                    Custom Formula Templates allow companies to define reusable pricing formulas in Company Settings &rarr; Custom Formulas.
                 </div>
             </div>
         </div>