Mix approvals into inbox activity feed

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/lib/inbox.test.ts

@@ -3,8 +3,9 @@
 import { beforeEach, describe, expect, it } from "vitest";
 import type { Approval, DashboardSummary, HeartbeatRun, Issue, JoinRequest } from "@paperclipai/shared";
 import {
-  getApprovalsForTab,
   computeInboxBadgeData,
+  getApprovalsForTab,
+  getInboxWorkItems,
   getRecentTouchedIssues,
   getUnreadTouchedIssues,
   loadLastInboxTab,
@@ -271,6 +272,31 @@ describe("inbox helpers", () => {
     ]);
   });
 
+  it("mixes approvals into the inbox feed by most recent activity", () => {
+    const newerIssue = makeIssue("1", true);
+    newerIssue.lastExternalCommentAt = new Date("2026-03-11T04:00:00.000Z");
+
+    const olderIssue = makeIssue("2", false);
+    olderIssue.lastExternalCommentAt = new Date("2026-03-11T02:00:00.000Z");
+
+    const approval = makeApprovalWithTimestamps(
+      "approval-between",
+      "pending",
+      "2026-03-11T03:00:00.000Z",
+    );
+
+    expect(
+      getInboxWorkItems({
+        issues: [olderIssue, newerIssue],
+        approvals: [approval],
+      }).map((item) => item.kind === "issue" ? `issue:${item.issue.id}` : `approval:${item.approval.id}`),
+    ).toEqual([
+      "issue:1",
+      "approval:approval-between",
+      "issue:2",
+    ]);
+  });
+
   it("can include sections on recent without forcing them to be unread", () => {
     expect(
       shouldShowInboxSection({

ui/src/lib/inbox.ts

@@ -13,6 +13,17 @@ export const DISMISSED_KEY = "paperclip:inbox:dismissed";
 export const INBOX_LAST_TAB_KEY = "paperclip:inbox:last-tab";
 export type InboxTab = "recent" | "unread" | "all";
 export type InboxApprovalFilter = "all" | "actionable" | "resolved";
+export type InboxWorkItem =
+  | {
+      kind: "issue";
+      timestamp: number;
+      issue: Issue;
+    }
+  | {
+      kind: "approval";
+      timestamp: number;
+      approval: Approval;
+    };
 
 export interface InboxBadgeData {
   inbox: number;
@@ -126,6 +137,45 @@ export function getApprovalsForTab(
   });
 }
 
+export function approvalActivityTimestamp(approval: Approval): number {
+  const updatedAt = normalizeTimestamp(approval.updatedAt);
+  if (updatedAt > 0) return updatedAt;
+  return normalizeTimestamp(approval.createdAt);
+}
+
+export function getInboxWorkItems({
+  issues,
+  approvals,
+}: {
+  issues: Issue[];
+  approvals: Approval[];
+}): InboxWorkItem[] {
+  return [
+    ...issues.map((issue) => ({
+      kind: "issue" as const,
+      timestamp: issueLastActivityTimestamp(issue),
+      issue,
+    })),
+    ...approvals.map((approval) => ({
+      kind: "approval" as const,
+      timestamp: approvalActivityTimestamp(approval),
+      approval,
+    })),
+  ].sort((a, b) => {
+    const timestampDiff = b.timestamp - a.timestamp;
+    if (timestampDiff !== 0) return timestampDiff;
+
+    if (a.kind === "issue" && b.kind === "issue") {
+      return sortIssuesByMostRecentActivity(a.issue, b.issue);
+    }
+    if (a.kind === "approval" && b.kind === "approval") {
+      return approvalActivityTimestamp(b.approval) - approvalActivityTimestamp(a.approval);
+    }
+
+    return a.kind === "approval" ? -1 : 1;
+  });
+}
+
 export function shouldShowInboxSection({
   tab,
   hasItems,