fix: correctly pass client.id when creating target in ClientTargetPanel

The ClientTargetPanel component now properly uses the client prop to access
client.id when creating a new target, instead of trying to access target?.clientId
which would be undefined during creation. This ensures new targets are properly
associated with the correct client.

frontend/src/pages/ClientsPage.tsx

@@ -66,6 +66,7 @@ const WEEKDAY_FULL_NAMES = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Frida
 
 // Inline target panel shown inside each client card
 function ClientTargetPanel({
+  client,
   target,
   onCreated,
   onDeleted,
@@ -159,7 +160,7 @@ function ClientTargetPanel({
         });
       } else {
         await onCreated({
-          clientId: target?.clientId || '',
+          clientId: client.id,
           periodType: formPeriodType,
           targetHours: hours,
           startDate: formStartDate,