feat: send security lockout emails to all admin users

shop/lib/actions/auth.ts

@@ -35,8 +35,23 @@ export async function signIn(email: string, password: string) {
           .from('users')
           .update({ role: 'gesperrt' })
           .eq('email', email)
-        // Notify admin
-        await sendLockoutEmail('info@hephex.de')
+        // Notify all admins
+        try {
+          const adminClient = createAdminClient()
+          const { data: admins } = await adminClient
+            .from('users')
+            .select('email')
+            .eq('role', 'admin')
+          
+          if (admins && admins.length > 0) {
+            const adminEmails = admins.map(a => a.email).filter(Boolean)
+            for (const adminEmail of adminEmails) {
+              await sendLockoutEmail(adminEmail)
+            }
+          }
+        } catch (mailError) {
+          console.error('Failed to notify admins of lockout:', mailError)
+        }
         return { success: false, error: 'Konto gesperrt nach 5 Fehlversuchen.' }
       }