feat(sms): implement SMS messaging and metered billing

Implement a complete SMS messaging system including:
- Integration with SMS Manager.cz API for sending messages.
- Metered billing via Stripe using monthly aggregate invoice items.
- Backend services for managing SMS settings, usage logging, and monthly reporting.
- Database migrations for tenant settings, usage logs, and monthly reports.
- Frontend dashboard components for SMS configuration, usage tracking, and history.
- Support for customer phone numbers in the booking flow.

Includes new migrations, backend services, and frontend UI components.

apps/backend/internal/db/bookings.go

@@ -1,14 +1,14 @@
 package db
 
 import (
-"context"
-"time"
+	"context"
+	"time"
 )
 
 func (r *PGRepository) ListBookingsByTenantBetween(ctx context.Context, tenantID string, from time.Time, to time.Time) ([]BookingRecord, error) {
 	rows, err := r.pool.Query(ctx, `
 		SELECT id, tenant_id, service_id, class_session_id, staff_id, location_id,
-		       customer_name, customer_email, starts_at, ends_at, status, reference
+		       customer_name, customer_email, customer_phone, starts_at, ends_at, status, reference
 		FROM bookings
 		WHERE tenant_id = $1 AND starts_at < $3 AND ends_at > $2
 		ORDER BY starts_at ASC
@@ -30,6 +30,7 @@ func (r *PGRepository) ListBookingsByTenantBetween(ctx context.Context, tenantID
 			&record.LocationID,
 			&record.CustomerName,
 			&record.CustomerEmail,
+			&record.CustomerPhone,
 			&record.StartsAt,
 			&record.EndsAt,
 			&record.Status,
@@ -47,10 +48,10 @@ func (r *PGRepository) CreateBooking(ctx context.Context, params CreateBookingPa
 	err := r.pool.QueryRow(ctx, `
 		INSERT INTO bookings (
 			tenant_id, service_id, class_session_id, staff_id, location_id,
-			booking_mode, customer_name, customer_email, starts_at, ends_at,
+			booking_mode, customer_name, customer_email, customer_phone, starts_at, ends_at,
 			status, reference, notes
 		)
-		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13)
+		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14)
 		RETURNING id, reference, status
 	`,
 		params.TenantID,
@@ -61,6 +62,7 @@ func (r *PGRepository) CreateBooking(ctx context.Context, params CreateBookingPa
 		params.BookingMode,
 		params.CustomerName,
 		params.CustomerEmail,
+		params.CustomerPhone,
 		params.StartsAt,
 		params.EndsAt,
 		params.Status,