fix: code quality and safety improvements

e2e/api.spec.ts

@@ -103,7 +103,8 @@ test("[API E2E] /api/auth/session returns a JSON object", async ({
 }) => {
   const res = await request.get("/api/auth/session");
   expect(res.status()).toBe(200);
-  const body = await res.json();
+  if (!res.ok) throw new Error("Request failed");
+const body = await res.json();
   // An unauthenticated session is an empty object {}, never null/undefined.
   expect(typeof body).toBe("object");
 });

src/lib/consistency-score.ts

@@ -133,7 +133,7 @@
   activeDates: Set<string>,
   timeZone = "UTC",
 ): ConsistencyScoreResult {
-  const sortedDates = Array.from(activeDates).sort();
+  const sortedDates = Array.from(activeDates).sort((a, b) => a - b);
   const today = todayInTimezone(timeZone);
 
   const weeklyConsistency = computeWeeklyConsistency(activeDates);

src/lib/date-utils.ts

@@ -249,7 +249,7 @@
     return `${yyyy}-${mm}-${dd}`;
   })();
 
-  const uniqueDates = [...new Set(dates)].sort().reverse();
+  const uniqueDates = [...new Set(dates)].sort((a, b) => a - b).reverse();
 
   if (uniqueDates[0] !== today && uniqueDates[0] !== yesterday) {
     return 0;

src/lib/streak-utils.ts

@@ -20,7 +20,7 @@
     if (key) dayKeys.add(key);
   }
 
-  return Array.from(dayKeys).sort();
+  return Array.from(dayKeys).sort((a, b) => a - b);
 }
 
 function getRuns(dates: StreakDate[]): { end: string; length: number }[] {

src/lib/streak.ts

@@ -62,7 +62,7 @@
     ...Array.from(activeDates),
     ...Array.from(freezeDates),
   ]);
-  const commitDays = Array.from(combinedDates).sort();
+  const commitDays = Array.from(combinedDates).sort((a, b) => a - b);
 
   if (commitDays.length === 0) {
     return {