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.Core/Entities/EmployeeClockEntry.cs

@@ -0,0 +1,24 @@
+namespace PowderCoating.Core.Entities;
+
+/// <summary>
+/// Facility-level clock-in/clock-out record for an employee.
+/// Tracks when an employee arrives and leaves the facility — separate from JobTimeEntry which tracks
+/// hours against a specific job. Multiple entries per day are fully supported (lunch breaks, etc.).
+/// The only enforced constraint: a user may not have more than one open entry (ClockOutTime == null) at a time.
+/// </summary>
+public class EmployeeClockEntry : BaseEntity
+{
+    public string UserId { get; set; } = string.Empty;
+
+    public DateTime ClockInTime { get; set; }
+
+    /// <summary>Null means the employee is currently clocked in.</summary>
+    public DateTime? ClockOutTime { get; set; }
+
+    /// <summary>Stored at clock-out time: (ClockOutTime - ClockInTime) in hours, rounded to 2 decimal places.</summary>
+    public decimal? HoursWorked { get; set; }
+
+    public string? Notes { get; set; }
+
+    public virtual ApplicationUser User { get; set; } = null!;
+}