Quizzes: To do = started but unfinished; durations roll into days

The To do tab now lists only quizzes you've started and not finished;
untouched ones stay under All. Quiz times show hours and days
(3h 20m, 2d 4h) instead of ever-growing minutes, and 59.96s no longer
prints as "60.0s".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/(app)/quizzes/quizzes-list.tsx

@@ -57,7 +57,9 @@ export function QuizzesList() {
           ? true
           : filter === "done"
             ? q.my.state === "completed"
-            : q.my.state !== "completed",
+            : // To do: started but not finished. Untouched quizzes live
+              // under All.
+              q.my.state === "in_progress",
       ),
     [list, filter],
   );

components/quiz/quiz-result-view.tsx

@@ -14,10 +14,24 @@ import { RichText } from "@/lib/rich-text";
 import type { QuizResult } from "@/lib/quiz";
 import { cn } from "@/lib/utils";
 
+/**
+ * "8.4s" / "1m 12s" / "3h 20m" / "2d 4h". Hours past 23h 59m roll up into
+ * days. Mirrors fmtMs in the admin's quizzes/labels.ts.
+ */
 export function fmtMs(ms?: number | null): string {
   if (ms == null) return "—";
-  if (ms < 60_000) return `${(ms / 1000).toFixed(1)}s`;
-  return `${Math.floor(ms / 60_000)}m ${Math.round((ms % 60_000) / 1000)}s`;
+  // Below 59.95s: one decimal place (anything higher would print "60.0s").
+  if (ms < 59_950) return `${(ms / 1000).toFixed(1)}s`;
+  // Whole seconds from here, so rounding can't print "1m 60s".
+  const total = Math.round(ms / 1000);
+  const d = Math.floor(total / 86_400);
+  const h = Math.floor((total % 86_400) / 3600);
+  const m = Math.floor((total % 3600) / 60);
+  const s = total % 60;
+  // The two largest units: 2d 4h · 3h 20m · 12m 5s.
+  if (d > 0) return `${d}d ${h}h`;
+  if (h > 0) return `${h}h ${m}m`;
+  return `${m}m ${s}s`;
 }
 
 export function QuizResultView({ result }: { result: QuizResult }) {