Add SMS gating, TCPA terms agreement, and compose-before-send modal

- Three-tier SMS gate: platform kill-switch → admin force-disable → plan AllowSms → company opt-in
- CompanySmsAgreement entity records admin acceptance of TCPA terms with IP, user agent, and terms version
- SMS terms of service modal on Company Settings with versioned re-agreement (AppConstants.SmsTermsVersion)
- Dev redirect: non-production SMS routed to Twilio:DevRedirectPhone to protect real customer numbers
- Removed redundant Ready for Pickup SMS (Job Completed covers it)
- Role-based compose modal on job completion: Admin/Manager reviews and edits before send; ShopFloor auto-sends
- Send SMS button on job details for ad-hoc messages (Admin/Manager only)
- SendJobSmsAsync auto-appends STOP opt-out language if missing
- Migrations: AddSmsGating, AddCompanySmsAgreement

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

src/PowderCoating.Application/DTOs/Job/JobDtos.cs

@@ -52,6 +52,10 @@ public class JobDto
     public bool RequiresCustomerApproval { get; set; }
     public bool IsCustomerApproved { get; set; }
 
+    // Customer SMS opt-in — used for SMS compose modal on job details
+    public bool CustomerNotifyBySms { get; set; }
+    public string? CustomerMobilePhone { get; set; }
+
     // Job Completion Details
     public decimal? ActualTimeSpentHours { get; set; }
 
@@ -380,6 +384,13 @@ public class CompleteJobDto
     public bool SendEmailToCustomer { get; set; } = false;
 }
 
+// DTO for the Admin/Manager compose-before-send SMS endpoint
+public class SendJobSmsRequest
+{
+    public int JobId { get; set; }
+    public string Message { get; set; } = string.Empty;
+}
+
 // DTO for tracking actual powder usage per coat
 public class JobItemCoatUsageDto
 {