Adds EventId type for robust event ID handling

Introduces type-safe EventId with centralized normalization logic for clone and standard event IDs

Refactors event ID management across multiple components to use consistent ID transformation methods
Improves type safety and reduces potential ID-related bugs in drag-and-drop and event rendering

src/types/EventId.ts

@@ -0,0 +1,31 @@
+/**
+ * Branded type for Event IDs
+ * Ensures type-safety and centralizes ID normalization logic
+ */
+export type EventId = string & { readonly __brand: 'EventId' };
+
+/**
+ * EventId utility functions
+ */
+export const EventId = {
+  /**
+   * Create EventId from string, normalizing clone- prefix
+   */
+  from(id: string): EventId {
+    return id.replace('clone-', '') as EventId;
+  },
+
+  /**
+   * Check if raw ID is a clone
+   */
+  isClone(id: string): boolean {
+    return id.startsWith('clone-');
+  },
+
+  /**
+   * Create clone ID string from EventId
+   */
+  toCloneId(id: EventId): string {
+    return `clone-${id}`;
+  }
+};