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.Web/Middleware/SubscriptionMiddleware.cs

@@ -91,6 +91,7 @@ public class SubscriptionMiddleware
         {
             context.Items["AllowOnlinePayments"] = true;
             context.Items["AllowAccounting"]     = true;
+            context.Items["AllowSms"]            = true;
             await _next(context);
             return;
         }
@@ -137,6 +138,9 @@ public class SubscriptionMiddleware
                 || (company.OnlinePaymentsOverride ?? (planConfig?.AllowOnlinePayments ?? false));
             context.Items["AllowAccounting"]     = company.IsComped
                 || (company.AccountingOverride ?? (planConfig?.AllowAccounting ?? false));
+            // SMS: comped gets it; admin force-disable beats everything else; then plan; then company opt-in
+            context.Items["AllowSms"]            = company.IsComped
+                || (!company.SmsDisabledByAdmin && (planConfig?.AllowSms ?? false) && company.SmsEnabled);
 
             if (company.IsComped)
             {