ci: restore timing summary artifact (#87832)

* ci: restore timing summary artifact

* ci: report pnpm warmup fanout timing

* ci: run timing summary from trusted base

test/scripts/ci-run-timings.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import {
   parseRunTimingArgs,
   selectLatestMainPushCiRun,
+  summarizePnpmStoreWarmupBarrier,
   summarizeRunTimings,
 } from "../../scripts/ci-run-timings.mjs";
 
@@ -80,6 +81,71 @@ describe("scripts/ci-run-timings.mjs", () => {
     });
   });
 
+  it("summarizes the pnpm store warmup fanout barrier", () => {
+    expect(
+      summarizePnpmStoreWarmupBarrier({
+        conclusion: "success",
+        createdAt: "2026-05-28T23:03:01Z",
+        jobs: [
+          {
+            completedAt: "2026-05-28T23:04:05Z",
+            conclusion: "success",
+            name: "preflight",
+            startedAt: "2026-05-28T23:03:55Z",
+            status: "completed",
+          },
+          {
+            completedAt: "2026-05-28T23:04:27Z",
+            conclusion: "success",
+            name: "pnpm-store-warmup",
+            startedAt: "2026-05-28T23:04:07Z",
+            status: "completed",
+          },
+          {
+            completedAt: "2026-05-28T23:06:26Z",
+            conclusion: "success",
+            name: "checks-fast-bundled-protocol",
+            startedAt: "2026-05-28T23:04:29Z",
+            status: "completed",
+          },
+          {
+            completedAt: "2026-05-28T23:04:28Z",
+            conclusion: "skipped",
+            name: "check-docs",
+            startedAt: "2026-05-28T23:04:28Z",
+            status: "completed",
+          },
+          {
+            completedAt: "2026-05-28T23:04:35Z",
+            conclusion: "success",
+            name: "security-fast",
+            startedAt: "2026-05-28T23:03:55Z",
+            status: "completed",
+          },
+          {
+            completedAt: "2026-05-28T23:05:30Z",
+            conclusion: "success",
+            name: "checks-node-compat-node22",
+            startedAt: "2026-05-28T23:04:30Z",
+            status: "completed",
+          },
+        ],
+        status: "completed",
+        updatedAt: "2026-05-28T23:07:33Z",
+      }),
+    ).toEqual({
+      activePostWarmupJobCount: 1,
+      firstPostWarmupStartDelaySeconds: 2,
+      postWarmupP95StartDelaySeconds: 2,
+      postWarmupStartedWithinWindow: 1,
+      preflightToWarmupCompleteSeconds: 22,
+      preflightToWarmupStartSeconds: 2,
+      warmupDurationSeconds: 20,
+      warmupResult: "completed/success",
+      windowSeconds: 5,
+    });
+  });
+
   it("falls back to the newest push CI run when the exact SHA has not appeared yet", () => {
     expect(
       selectLatestMainPushCiRun(

test/scripts/ci-workflow-guards.test.ts

@@ -47,6 +47,58 @@ describe("ci workflow guards", () => {
     expect(buildArtifactSteps.some((step) => step.run === "pnpm ui:build")).toBe(false);
   });
 
+  it("uploads a CI timing summary after the run lanes finish", () => {
+    const workflow = readCiWorkflow();
+    const timingJob = workflow.jobs["ci-timings-summary"];
+
+    expect(timingJob.permissions).toMatchObject({ actions: "read", contents: "read" });
+    expect(timingJob.needs).toEqual([
+      "preflight",
+      "security-fast",
+      "pnpm-store-warmup",
+      "build-artifacts",
+      "checks-fast-core",
+      "checks-fast-plugin-contracts-shard",
+      "checks-fast-channel-contracts-shard",
+      "checks-node-compat",
+      "checks-node-core-test-nondist-shard",
+      "check-shard",
+      "check-additional-shard",
+      "check-docs",
+      "skills-python",
+      "checks-windows",
+      "macos-node",
+      "macos-swift",
+      "android",
+    ]);
+    expect(timingJob.if).toContain("always()");
+    expect(timingJob.if).toContain("!cancelled()");
+
+    const checkoutStep = timingJob.steps.find(
+      (step) => step.name === "Checkout timing summary helper",
+    );
+    expect(checkoutStep.uses).toBe("actions/checkout@v6");
+    expect(checkoutStep.with.ref).toBe(
+      "${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || needs.preflight.outputs.checkout_revision || github.sha }}",
+    );
+    expect(checkoutStep.with["persist-credentials"]).toBe(false);
+
+    const writeStep = timingJob.steps.find((step) => step.name === "Write CI timing summary");
+    expect(writeStep.env).toMatchObject({ GH_TOKEN: "${{ github.token }}" });
+    expect(writeStep.run).toContain(
+      'node scripts/ci-run-timings.mjs "$GITHUB_RUN_ID" --limit 25 > ci-timings-summary.txt',
+    );
+    expect(writeStep.run).toContain('cat ci-timings-summary.txt >> "$GITHUB_STEP_SUMMARY"');
+
+    const uploadStep = timingJob.steps.find((step) => step.name === "Upload CI timing summary");
+    expect(uploadStep.uses).toBe("actions/upload-artifact@v7");
+    expect(uploadStep.with).toMatchObject({
+      name: "ci-timings-summary",
+      path: "ci-timings-summary.txt",
+      "retention-days": 14,
+    });
+  });
+
   it("keeps push docs validation ClawHub-backed", () => {
     const workflow = readFileSync(".github/workflows/docs.yml", "utf8");