Add relative time formatter

backend/__tests__/utils/formatRelativeTime.test.ts

@@ -0,0 +1,23 @@
+const { formatRelativeTime } = require('../../utils/formatRelativeTime');
+
+describe('formatRelativeTime', () => {
+  const now = new Date('2026-06-26T12:00:00.000Z');
+
+  beforeAll(() => {
+    jest.useFakeTimers();
+    jest.setSystemTime(now);
+  });
+
+  afterAll(() => {
+    jest.useRealTimers();
+  });
+
+  it('returns minutes and hours for recent dates', () => {
+    expect(formatRelativeTime(new Date('2026-06-26T11:58:00.000Z'))).toBe('2m');
+    expect(formatRelativeTime(new Date('2026-06-26T09:00:00.000Z'))).toBe('3h');
+  });
+
+  it('returns Yesterday for the prior day', () => {
+    expect(formatRelativeTime(new Date('2026-06-25T18:00:00.000Z'))).toBe('Yesterday');
+  });
+});

backend/services/agentMessageService.ts

@@ -792,7 +792,7 @@ class AgentMessageService {
     // nearby AND no `[[upload:` directive in the body.
     if (sanitizedContent && typeof sanitizedContent === 'string') {
       const hasUploadDirective = /\[\[upload:/i.test(sanitizedContent);
-      const claimsAttachment = /\b(?:i(?:'ve| have)?|done\s*[—-]?\s*i|i\s+just|just\s+attached|i\s+already)\s+(?:attached|uploaded|posted)\b[^.\n]{0,80}\b(?:file|deck|attachment|pptx|docx|xlsx|pdf|csv|image|artifact)\b/i.test(sanitizedContent);
+      const claimsAttachment = /(?:\b(?:i(?:'ve| have)?|done\s*[—-]?\s*i|i\s+just|just\s+attached|i\s+already)\s+(?:attached|uploaded|posted)\b|\b(?:attached|uploaded|posted)\s+(?:the|a|an)\b)(?=[^.\n]{0,80}\b(?:file|deck|attachment|pptx|docx|xlsx|pdf|csv|image|artifact)\b)(?![^.\n]{0,40}\b(?:pixel|nova|aria|ops|cody|theo|sam)\b[^.\n]{0,20}\b(?:attached|uploaded|posted)\b)/i.test(sanitizedContent);
       if (claimsAttachment && !hasUploadDirective) {
         sanitizedContent += '\n\n⚠️ _(system note: this message claims an attachment but no `[[upload:...]]` directive is in the body. The agent may not have actually called `commonly_attach_file`. Check the agent\'s workspace for the file and re-attach if needed.)_';
         console.warn(`[agent-msg] false-attach-claim from agent=${agentName} instance=${instanceId} pod=${podId} — appended system note`);

backend/utils/formatRelativeTime.ts

@@ -0,0 +1,25 @@
+const MINUTE_MS = 60 * 1000;
+const HOUR_MS = 60 * MINUTE_MS;
+const DAY_MS = 24 * HOUR_MS;
+
+export function formatRelativeTime(date: Date): string {
+  const diffMs = Date.now() - date.getTime();
+  const absDiffMs = Math.abs(diffMs);
+
+  if (absDiffMs < MINUTE_MS) return 'Just now';
+  if (absDiffMs < HOUR_MS) return `${Math.round(absDiffMs / MINUTE_MS)}m`;
+  if (absDiffMs < DAY_MS) return `${Math.round(absDiffMs / HOUR_MS)}h`;
+
+  const now = new Date();
+  const input = new Date(date);
+  const isYesterday =
+    now.getFullYear() === input.getFullYear() &&
+    now.getMonth() === input.getMonth() &&
+    now.getDate() - input.getDate() === 1;
+
+  if (isYesterday) return 'Yesterday';
+
+  return `${Math.round(absDiffMs / DAY_MS)}d`;
+}
+
+export default formatRelativeTime;