iCal Subscription: Display an External Calendar as Read-Only in the Dashboard Calendar

**Problem / Use Case** In addition to HalloPetra, customers use other calendars (e.g., Outlook, Google, or contractor software). These appointments are currently not visible in the HalloPetra dashboard. The request: to integrate an external calendar via an **iCal subscription link (webcal/.ics)** and display it in the dashboard’s calendar view **for viewing only** (read-only). **Expected Benefits** - Complete overview of appointments in one place → fewer double bookings / context when viewing the calendar - No maintenance required: enter the subscription link once, and appointments update automatically - Explicitly read-only desired – visibility alone is sufficient for the customer **General Concept** - Store one or more iCal subscription URLs per company - Render events as a separate, clearly distinguishable overlay layer in the dashboard calendar (non-editable, with a custom color/source if needed) - Regular synchronization of the feed **Source:** Customer inquiry via Regnauer Fertigbau GmbH & CO. KG **Open:** Which specific calendar should be integrated, and for what exact purpose (e.g., to view installer/construction site appointments)?