fix: replace {__} workaround with clean range() helper in Svelte templates

frontend/src/lib/utils/format.ts

@@ -80,3 +80,19 @@ export function calculateAge(dateOfBirth: string | undefined | null): number | n
 	}
 	return age;
 }
+
+/**
+ * Create an array of numbers from 0 to n-1.
+ *
+ * Useful for iterating a fixed number of times in Svelte templates:
+ *
+ *   {#each range(3) as i}
+ *     <div>{i}</div>
+ *   {/each}
+ *
+ * Replaces the `{#each Array(3) as _, i (i)}{__}{/each}` workaround pattern
+ * that was needed to suppress eslint unused-variable warnings.
+ */
+export function range(n: number): number[] {
+	return Array.from({ length: n }, (_, i) => i);
+}