feat(#1): Set up monorepo scaffold with pnpm workspaces + TurboRepo

Implements the foundational project structure including:
- pnpm workspaces configuration
- TurboRepo for build orchestration
- NestJS 11.1.12 API (apps/api)
- Next.js 16.1.6 web app (apps/web)
- Shared packages (config, shared, ui)
- TypeScript strict mode configuration
- ESLint + Prettier setup
- Vitest for unit testing (19 passing tests)

Fixes #1

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/shared/src/utils/index.ts

@@ -0,0 +1,35 @@
+/**
+ * Safely parse a date string or return undefined
+ */
+export function parseDate(value: string | Date | undefined | null): Date | undefined {
+  if (!value) return undefined;
+  if (value instanceof Date) return value;
+  const parsed = new Date(value);
+  return isNaN(parsed.getTime()) ? undefined : parsed;
+}
+
+/**
+ * Generate a simple slug from a string
+ */
+export function slugify(text: string): string {
+  return text
+    .toLowerCase()
+    .trim()
+    .replace(/[^\w\s-]/g, "")
+    .replace(/[\s_-]+/g, "-")
+    .replace(/^-+|-+$/g, "");
+}
+
+/**
+ * Sleep for a given number of milliseconds
+ */
+export function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+/**
+ * Check if a value is defined (not null or undefined)
+ */
+export function isDefined<T>(value: T | null | undefined): value is T {
+  return value !== null && value !== undefined;
+}