feat: add vitest, vite, move to tdd

src/utils/markdown.ts

@@ -1,5 +1,11 @@
 import matter from "gray-matter";
-import { Task } from "../model/task";
+import { Task } from "@/model/task";
+
+function toISO(value: unknown): string {
+	if (value instanceof Date) return value.toISOString();
+	if (typeof value === "string") return value;
+	return new Date().toISOString();
+}
 
 export function parseTaskFile(content: string): Task {
 	const parsed = matter(content);
@@ -11,8 +17,8 @@ export function parseTaskFile(content: string): Task {
 		priority: parsed.data.priority ?? "medium",
 		tags: parsed.data.tags ?? [],
 		assignee: parsed.data.assignee ?? "",
-		created: parsed.data.created ?? new Date().toISOString(),
-		updated: parsed.data.updated ?? new Date().toISOString(),
+		created: toISO(parsed.data.created),
+		updated: toISO(parsed.data.updated),
 	};
 }