ci(nightly): repair five job classes broken by the #649 QA hardening (#695)

Nightly has been red since 07-28; per-PR CI and main are green. Two investigations traced all five failing classes to #649: extended-matrix required AI bundles it never installs (removed), nightly SYSTEM_DEPS drifted from ci.yml (added libreoffice + a doc-binaries composite for pandoc/pdfcpu), the generated-case classifier only skipped ffmpeg (widened to pdfcpu/soffice/pandoc + excluded repo-audit specs from the lean docker image), a settings spec capped loginAttemptLimit and 429-cascaded the serial bucket (restore via API), and type-to-search refused keystrokes under a route announcer's programmatic focus (guard added). A nightly dispatch on the branch confirmed all five classes green.

tests/unit/helpers/generated-case-accounting.test.ts

@@ -2,8 +2,35 @@ import { describe, expect, it } from "vitest";
 import {
   featureUnavailableDisposition,
   GeneratedCaseAccounting,
+  isEngineUnavailableFailure,
 } from "../../helpers/generated-case-accounting.js";
 
+describe("isEngineUnavailableFailure", () => {
+  // The lean docker test image skips binary-gated tools by design, so every
+  // spawn engine gates the same way ffmpeg does: a missing binary is a skip,
+  // not a product failure. A real crash (exit code + stderr) still fails.
+  it.each([
+    "ffmpeg binary not found (set FFMPEG_PATH or install ffmpeg)",
+    "pdfcpu binary not found (set PDFCPU_PATH or install pdfcpu)",
+    "soffice binary not found (set SOFFICE_PATH or install LibreOffice)",
+  ])("treats a missing-binary message as engine-unavailable: %s", (message) => {
+    expect(isEngineUnavailableFailure(new Error(message))).toBe(true);
+  });
+
+  it.each(["spawn pandoc ENOENT", "spawn /usr/local/bin/pdfcpu ENOENT", "spawn soffice ENOENT"])(
+    "treats a spawn ENOENT for a known engine as engine-unavailable: %s",
+    (message) => {
+      expect(isEngineUnavailableFailure(new Error(message))).toBe(true);
+    },
+  );
+
+  it("keeps a real processing crash a failure", () => {
+    expect(
+      isEngineUnavailableFailure(new Error("pdfcpu exited with code 1: invalid page range")),
+    ).toBe(false);
+  });
+});
+
 describe("GeneratedCaseAccounting", () => {
   it("fails a tool that executes no generated cases", () => {
     const accounting = new GeneratedCaseAccounting("resize");

tests/unit/helpers/generated-harness-contract.test.ts

@@ -70,12 +70,16 @@ describe("generated QA harness contract", () => {
     expect(text).not.toContain("describe.skip(");
   });
 
-  it("the actual nightly extended lane requires installed AI features", () => {
+  it("the nightly extended lane does not require AI features it never installs", () => {
+    // Strict required-AI mode (absence of a bundle is a failure) is only valid
+    // on a host with bundles installed, which is the release-QA fleet. The
+    // extended-matrix lane has no bundle-install step, so requiring them there
+    // 501s every installed-contract case on a bundle-less runner.
     const workflow = readFileSync(join(process.cwd(), ".github/workflows/nightly.yml"), "utf8");
     const extendedLane = workflow.slice(
       workflow.indexOf("  extended-matrix:"),
       workflow.indexOf("  api-fuzz:"),
     );
-    expect(extendedLane).toContain('REQUIRE_AI_FEATURES: "1"');
+    expect(extendedLane).not.toContain("REQUIRE_AI_FEATURES");
   });
 });