feat: Add UI for /stats slash command (#883)

packages/cli/src/ui/utils/formatters.ts

@@ -14,3 +14,50 @@ export const formatMemoryUsage = (bytes: number): string => {
   }
   return `${gb.toFixed(2)} GB`;
 };
+
+/**
+ * Formats a duration in milliseconds into a concise, human-readable string (e.g., "1h 5s").
+ * It omits any time units that are zero.
+ * @param milliseconds The duration in milliseconds.
+ * @returns A formatted string representing the duration.
+ */
+export const formatDuration = (milliseconds: number): string => {
+  if (milliseconds <= 0) {
+    return '0s';
+  }
+
+  if (milliseconds < 1000) {
+    return `${milliseconds}ms`;
+  }
+
+  const totalSeconds = milliseconds / 1000;
+
+  if (totalSeconds < 60) {
+    return `${totalSeconds.toFixed(1)}s`;
+  }
+
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = Math.floor(totalSeconds % 60);
+
+  const parts: string[] = [];
+
+  if (hours > 0) {
+    parts.push(`${hours}h`);
+  }
+  if (minutes > 0) {
+    parts.push(`${minutes}m`);
+  }
+  if (seconds > 0) {
+    parts.push(`${seconds}s`);
+  }
+
+  // If all parts are zero (e.g., exactly 1 hour), return the largest unit.
+  if (parts.length === 0) {
+    if (hours > 0) return `${hours}h`;
+    if (minutes > 0) return `${minutes}m`;
+    return `${seconds}s`;
+  }
+
+  return parts.join(' ');
+};