diff --git a/web/.env.example b/web/.env.example
index 3e9c855..b93653f 100644
--- a/web/.env.example
+++ b/web/.env.example
@@ -3,3 +3,4 @@
 
 # Platform Service (backend API for sync, auth, telemetry)
 NEXT_PUBLIC_PLATFORM_SERVICE_URL=http://localhost:4003/api
+NEXT_PUBLIC_PRODUCT_ID=chronomind
diff --git a/web/src/lib/stats.test.ts b/web/src/lib/stats.test.ts
index 1851aeb..a64ecaa 100644
--- a/web/src/lib/stats.test.ts
+++ b/web/src/lib/stats.test.ts
@@ -294,7 +294,9 @@ describe('computeWeeklySummary', () => {
   it('identifies top category', () => {
     const now = Date.now();
     const weekStart = new Date(now);
-    weekStart.setDate(weekStart.getDate() - weekStart.getDay() + 1); // Monday
+    const day = weekStart.getDay(); // 0=Sun
+    const diff = day === 0 ? 6 : day - 1; // match getWeekStart logic
+    weekStart.setDate(weekStart.getDate() - diff); // Monday
     weekStart.setHours(12, 0, 0, 0);
 
     const timers = [