feat: add plan title and interval editing to settings

- Add Settings button label i18n (de: Einstellungen)
- Allow editing plan title, feeding per day, feeding interval, and litter interval
- Update PlanSettings component with new form fields
- Add German and English translations for new settings
- Update Plan type to include title property

app/[lang]/dashboard/[planId]/_components/plan-dashboard.tsx

@@ -32,6 +32,7 @@ type Booking = {
 
 type Plan = {
     id: string
+    title: string
     startDate: Date
     endDate: Date
     instructions: string | null
@@ -161,9 +162,13 @@ export function PlanDashboard({ plan, dict, settingsDict, lang }: PlanDashboardP
                     </Button>
                     <PlanSettings
                         planId={plan.id}
+                        initialTitle={plan.title}
                         initialWebhookUrl={plan.webhookUrl}
                         initialInstructions={plan.instructions}
                         initialNotifyAll={plan.notifyAll}
+                        initialFeedingPerDay={plan.feedingPerDay}
+                        initialFeedingInterval={plan.feedingInterval}
+                        initialLitterInterval={plan.litterInterval}
                         dict={settingsDict}
                         lang={lang}
                     />