@@ -20,6 +20,10 @@
       "types": "./src/archive.ts",
       "default": "./src/archive.ts"
     },
+    "./archive-fixtures": {
+      "types": "./src/archive.fixtures.ts",
+      "default": "./src/archive.fixtures.ts"
+    },
     "./audio-probe-fixtures": {
       "types": "./src/audio-probe.fixtures.ts",
       "default": "./src/audio-probe.fixtures.ts"
 
@@ -3,8 +3,7 @@ import { promises as fs } from 'node:fs';
 import path from 'node:path';
 import { crc32, gzipSync } from 'node:zlib';
 import * as tar from 'tar-stream';
-import { runCmdSync } from './exec.ts';
-import { mkdtempForTest } from './tmp-dir.fixtures.ts';
+import { mkdtempForTest } from './internal/tmp-dir.fixtures.ts';
 
 export async function createArchiveWorkspace(): Promise<{
   archivePath: string;
@@ -27,21 +26,30 @@ export async function createTruncatedTgz(archivePath: string): Promise<void> {
   await fs.writeFile(archivePath, gzipSync(headerOnly));
 }
 
+/** Two stored entries whose second carries the encrypted general-purpose flag bit. */
 export async function createZipWithEncryptedSecondEntry(archivePath: string): Promise<void> {
-  const staging = path.join(path.dirname(archivePath), 'zip-input');
-  await fs.mkdir(staging);
-  await fs.writeFile(path.join(staging, 'first.txt'), 'first');
-  await fs.writeFile(path.join(staging, 'second.txt'), 'second');
-  runCmdSync('zip', ['-q', archivePath, 'first.txt'], { cwd: staging });
-  runCmdSync('zip', ['-q', '-P', 'secret', archivePath, 'second.txt'], { cwd: staging });
+  await writeZipFixture(archivePath, [
+    { name: 'first.txt', mode: ZIP_FILE_MODE, data: 'first' },
+    { name: 'second.txt', mode: ZIP_FILE_MODE, data: 'second', encrypted: true },
+  ]);
 }
 
+const ZIP_FILE_MODE = 0o100644;
+
 /** One stored zip entry; `mode` is the full Unix `st_mode`, file-type bits included. */
-export type ZipFixtureEntry = { name: string; mode: number; data?: string };
+export type ZipFixtureEntry = {
+  name: string;
+  mode: number;
+  data?: string;
+  /** Declares the entry encrypted, which no archive reader may then extract. */
+  encrypted?: boolean;
+};
 
 /**
  * Writes a stored (uncompressed) zip whose names and Unix attributes are exactly as given, which
- * `zip` itself refuses to produce for links, special files, and escaping names.
+ * `zip` itself refuses to produce for links, special files, and escaping names. An entry declared
+ * `encrypted` carries the traditional encryption flag with a padded 12-byte encryption header and
+ * a zero CRC, the shape readers must refuse before extracting anything.
  */
 export async function writeZipFixture(
   archivePath: string,
@@ -52,24 +60,29 @@ export async function writeZipFixture(
   let offset = 0;
   for (const entry of entries) {
     const name = Buffer.from(entry.name, 'utf8');
-    const data = Buffer.from(entry.data ?? '', 'utf8');
-    const checksum = crc32(data);
+    const payload = Buffer.from(entry.data ?? '', 'utf8');
+    // A traditionally encrypted stored entry carries a 12-byte encryption header before the
+    // ciphertext, and readers validate that against the declared sizes, so the record declares
+    // it and the data section pads it; the payload itself never decrypts to anything.
+    const data = entry.encrypted ? Buffer.concat([Buffer.alloc(12), payload]) : payload;
+    const checksum = entry.encrypted ? 0 : crc32(payload);
+    const flags = 0x0800 | (entry.encrypted ? 0x0001 : 0);
     const local = Buffer.alloc(30);
     local.writeUInt32LE(0x04034b50, 0);
     local.writeUInt16LE(20, 4);
-    local.writeUInt16LE(0x0800, 6);
+    local.writeUInt16LE(flags, 6);
     local.writeUInt32LE(checksum, 14);
     local.writeUInt32LE(data.length, 18);
-    local.writeUInt32LE(data.length, 22);
+    local.writeUInt32LE(payload.length, 22);
     local.writeUInt16LE(name.length, 26);
     const central = Buffer.alloc(46);
     central.writeUInt32LE(0x02014b50, 0);
     central.writeUInt16LE((3 << 8) | 20, 4);
     central.writeUInt16LE(20, 6);
-    central.writeUInt16LE(0x0800, 8);
+    central.writeUInt16LE(flags, 8);
     central.writeUInt32LE(checksum, 16);
     central.writeUInt32LE(data.length, 20);
-    central.writeUInt32LE(data.length, 24);
+    central.writeUInt32LE(payload.length, 24);
     central.writeUInt16LE(name.length, 28);
     central.writeUInt32LE((entry.mode << 16) >>> 0, 38);
     central.writeUInt32LE(offset, 42);
 
@@ -4,7 +4,7 @@ import { test } from 'vitest';
 import { AppError } from '@agent-device/kernel/errors';
 import { extractTarArchive } from './archive-extraction-tar.ts';
 import { ArchiveBudget } from './archive-safety.ts';
-import { createArchiveWorkspace, createTruncatedTgz } from './archive-extraction.fixtures.ts';
+import { createArchiveWorkspace, createTruncatedTgz } from '../archive.fixtures.ts';
 
 test('tar inspection rejects declared bytes before draining an over-budget entry', async () => {
   const workspace = await createArchiveWorkspace();
 
@@ -4,10 +4,7 @@ import { test } from 'vitest';
 import { AppError } from '@agent-device/kernel/errors';
 import { extractZipArchive } from './archive-extraction-zip.ts';
 import { ArchiveBudget } from './archive-safety.ts';
-import {
-  createArchiveWorkspace,
-  createZipWithEncryptedSecondEntry,
-} from './archive-extraction.fixtures.ts';
+import { createArchiveWorkspace, createZipWithEncryptedSecondEntry } from '../archive.fixtures.ts';
 
 test('zip inspection stops at the entry budget before inspecting later entries', async () => {
   const workspace = await createArchiveWorkspace();
 
@@ -9,7 +9,7 @@ import {
   writeZipFixture,
   type TarFixtureEntry,
   type ZipFixtureEntry,
-} from './archive-extraction.fixtures.ts';
+} from '../archive.fixtures.ts';
 import { mkdtempForTest } from './tmp-dir.fixtures.ts';
 
 const S_IFREG = 0o100000;
 
@@ -110,18 +110,22 @@ function bootPropFailure(stdout: string, stderr: string) {
   };
 }
 
-/** A poll that keeps missing like a real booting device does, and actually burns wall-clock time. */
+/** A poll that keeps missing like a real booting device does and burns the given clock time. */
 function slowBootPropFailure(delayMs: number) {
   return async () => {
     await new Promise((resolve) => setTimeout(resolve, delayMs));
     return { stdout: '', stderr: '', exitCode: 1 };
   };
 }
 
-async function expectBootFailure(
+/**
+ * Starts the wait and resolves to the typed failure it must produce. The caller drives any timers
+ * between starting and awaiting when the test runs on a fake clock.
+ */
+function startedBootFailure(
   timeoutMs: number,
 ): Promise<{ code: string; message: string; details: Record<string, unknown> }> {
-  return await waitForAndroidBoot('emulator-5554', timeoutMs).then(
+  return waitForAndroidBoot('emulator-5554', timeoutMs).then(
     () => {
       throw new Error('expected waitForAndroidBoot to reject');
     },
@@ -133,6 +137,12 @@ async function expectBootFailure(
   );
 }
 
+async function expectBootFailure(
+  timeoutMs: number,
+): Promise<{ code: string; message: string; details: Record<string, unknown> }> {
+  return await startedBootFailure(timeoutMs);
+}
+
 test('a boot poll against an offline device fails as an adb transport loss without retrying', async () => {
   mockRunCmd.mockImplementation(bootPropFailure('', 'error: device offline'));
 
@@ -149,21 +159,28 @@ test('a boot poll against an offline device fails as an adb transport loss witho
 });
 
 test('a still-booting device past its deadline reports an Android boot timeout', async () => {
-  // 80 ms per poll with a 50 ms retry cadence crosses the 150 ms deadline inside the second
-  // poll, so the failure is a device that ran out of budget, not three fast poll misses.
-  mockRunCmd.mockImplementation(slowBootPropFailure(80));
-
-  const failure = await expectBootFailure(150);
-
-  assert.equal(failure.code, 'COMMAND_FAILED');
-  assert.equal(failure.message, 'Android device did not finish booting in time');
-  assert.equal(failure.details.reason, 'ANDROID_BOOT_TIMEOUT');
-  assert.equal(failure.details.timeoutMs, 150);
-  assert.equal(Number(failure.details.elapsedMs) >= 150, true);
-  assert.equal(mockRunCmd.mock.calls.length, 2);
-  // The classifier sees BOOT_COMMAND_FAILED from the still-booting throw; the caller must
-  // normalize it to the timeout, not trust the raw classification.
-  assert.notEqual(failure.details.reason, 'BOOT_COMMAND_FAILED');
+  // On a fake clock: each poll burns 80 ms, and the 150 ms deadline is crossed inside the
+  // second poll, so the failure is a device that ran out of budget, not a run of fast poll
+  // misses. Fake timers keep the 80 ms/150 ms geometry exact instead of racing the host.
+  vi.useFakeTimers();
+  try {
+    mockRunCmd.mockImplementation(slowBootPropFailure(80));
+
+    const started = startedBootFailure(150);
+    await vi.runAllTimersAsync();
+    const failure = await started;
+
+    assert.equal(failure.code, 'COMMAND_FAILED');
+    assert.equal(failure.message, 'Android device did not finish booting in time');
+    // The classifier sees BOOT_COMMAND_FAILED from the still-booting throw; the caller must
+    // normalize it to the timeout rather than trust the raw classification.
+    assert.equal(failure.details.reason, 'ANDROID_BOOT_TIMEOUT');
+    assert.equal(failure.details.timeoutMs, 150);
+    assert.equal(Number(failure.details.elapsedMs) >= 150, true);
+    assert.equal(mockRunCmd.mock.calls.length, 2);
+  } finally {
+    vi.useRealTimers();
+  }
 });
 
 test('a TOOL_MISSING adb inside the boot loop keeps its error code and hint', async () => {
 
@@ -2,7 +2,7 @@ import { test } from 'vitest';
 import assert from 'node:assert/strict';
 import fs from 'node:fs/promises';
 import path from 'node:path';
-import { runCmdSync } from '@agent-device/host-kit/command';
+import { writeZipFixture } from '@agent-device/host-kit/archive-fixtures';
 import { AppError } from '@agent-device/kernel/errors';
 import { createLocalAppleToolProvider, withAppleToolProvider } from '../tool-provider.ts';
 import { prepareIosInstallArtifact } from '../install-artifact.ts';
@@ -99,27 +99,29 @@ test('prepareIosInstallArtifact keeps a non-dotted hint a name-only match', asyn
 
 type PayloadBundleFixture = { name: string; bundleId?: string };
 
+const ZIP_DIR_MODE = 0o040000 | 0o755;
+const ZIP_FILE_MODE = 0o100644;
+
 /**
  * Builds a real zip-format IPA carrying the given `Payload/*.app` bundles and runs `run` against
- * it. Info.plist reads go through a fake tool provider keyed by the bundle's own directory, so
+ * it, written through host-kit's own zip fixture so the test needs no `zip` binary on the host.
+ * Info.plist reads go through a fake tool provider keyed by the bundle's own directory, so
  * each payload reports an identity of its own without plist tooling on the host.
  */
 async function withMultiPayloadIpa(
   bundles: PayloadBundleFixture[],
   run: (ipaPath: string) => Promise<void>,
 ): Promise<void> {
   const root = await mkdtempForTest('agent-device-ios-multi-payload-');
-  const staging = path.join(root, 'staging');
-  for (const bundle of bundles) {
-    const appDir = path.join(staging, 'Payload', `${bundle.name}.app`);
-    await fs.mkdir(appDir, { recursive: true });
-    await fs.writeFile(
-      path.join(appDir, 'Info.plist'),
-      '<?xml version="1.0" encoding="UTF-8"?><plist version="1.0"><dict/></plist>',
-    );
-  }
   const ipaPath = path.join(root, 'multi.ipa');
-  runCmdSync('zip', ['-qr', ipaPath, '.'], { cwd: staging });
+  await writeZipFixture(ipaPath, [
+    { name: 'Payload/', mode: ZIP_DIR_MODE },
+    ...bundles.map(({ name }) => ({
+      name: `Payload/${name}.app/Info.plist`,
+      mode: ZIP_FILE_MODE,
+      data: '<?xml version="1.0" encoding="UTF-8"?><plist version="1.0"><dict/></plist>',
+    })),
+  ]);
 
   const provider = createLocalAppleToolProvider({
     plist: {
 
@@ -1,5 +1,6 @@
 import { test } from 'vitest';
 import assert from 'node:assert/strict';
+import { AppError } from '@agent-device/kernel/errors';
 import { copyCoreDeviceRunnerFile } from '../physical-device-files.ts';
 import { IOS_DEVICE } from '../../__tests__/device-fixtures.ts';
 import { withFakeAppleTool, type FakeAppleToolScript } from '../../__tests__/fake-apple-tool.ts';
@@ -83,7 +84,16 @@ test('copyCoreDeviceRunnerFile refuses to start once the deadline is spent', asy
         async () => await copyCoreDeviceRunnerFile(IOS_DEVICE, '/tmp/shot.png', '/out/shot.png', 0),
         { device: IOS_DEVICE },
       ),
-    /iOS runner file copy timed out after 0ms/,
+    (error: unknown) => {
+      // The message alone says only "timed out"; the typed step is what tells the caller the
+      // spent deadline was the file copy's, not another phase of the physical-device flow.
+      assert.ok(error instanceof AppError);
+      assert.equal(error.code, 'COMMAND_FAILED');
+      assert.match(error.message, /iOS runner file copy timed out after 0ms/);
+      assert.equal(error.details?.step, 'runner file copy');
+      assert.equal(error.details?.timeoutMs, 0);
+      return true;
+    },
   );
   assert.deepEqual(calls, []);
 });