Make commit history easier to scan and review (#2146)

* feat(app): improve commit history and diff review

* fix(app): keep commit timestamps current

* fix(app): pause hidden commit clocks

* fix(app): reopen commit diff in persistence test

packages/app/src/utils/time.ts

@@ -2,8 +2,7 @@
  * Format a date as a human-friendly relative time string
  * Examples: "just now", "5m ago", "2h ago", "3d ago", "Jan 15"
  */
-export function formatTimeAgo(date: Date): string {
-  const now = new Date();
+export function formatTimeAgo(date: Date, now: Date = new Date()): string {
   const diffMs = now.getTime() - date.getTime();
   const diffSec = Math.floor(diffMs / 1000);
   const diffMin = Math.floor(diffSec / 60);