Prettify retry duration display in TUI (#8608)

Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>

packages/opencode/src/util/format.ts

@@ -0,0 +1,20 @@
+export function formatDuration(secs: number) {
+  if (secs <= 0) return ""
+  if (secs < 60) return `${secs}s`
+  if (secs < 3600) {
+    const mins = Math.floor(secs / 60)
+    const remaining = secs % 60
+    return remaining > 0 ? `${mins}m ${remaining}s` : `${mins}m`
+  }
+  if (secs < 86400) {
+    const hours = Math.floor(secs / 3600)
+    const remaining = Math.floor((secs % 3600) / 60)
+    return remaining > 0 ? `${hours}h ${remaining}m` : `${hours}h`
+  }
+  if (secs < 604800) {
+    const days = Math.floor(secs / 86400)
+    return days === 1 ? "~1 day" : `~${days} days`
+  }
+  const weeks = Math.floor(secs / 604800)
+  return weeks === 1 ? "~1 week" : `~${weeks} weeks`
+}