fix: address Android W5 review feedback

Author: thymikee

docs/adr/0019-request-bound-platform-runtime.md

@@ -183,7 +183,9 @@ execution, diagnostics, retry, probes, locks, foreground Apple tooling, physical
 constructed by exactly one composition root. No current issue owns migrating the runner's direct
 consumers behind the composition gateway; if such a migration retires them, the `./runner` seam
 narrows with it, but the facet itself is the intended ownership model, not a temporary exception.
-The declaration mechanism stays apple-specific until another family needs a mechanics facet.
+Mechanics-facet declarations are explicit per family: the Apple runner and Android mechanics/host
+facets are enumerated above, and a new family adds its own named facet only with an owning consumer
+and evidence.
 
 Canonical family, `AppleOS`, public-leaf, and selector identity remain declared in
 `@agent-device/kernel/device`. Platform-module metadata references one canonical family; during
@@ -678,6 +680,31 @@ removed against package bytes added; net growth is exceptional and each contribu
 named and justified individually. Contract modules stay vocabulary-thin under the existing
 capture-kit rule; per-unit type inflation is size growth and is reviewed as such.
 
+#### W5 Android family accounting (PR #2117)
+
+The W5 exact-head size report at `9fa2778` against `437465f37` reported these rounded CI values:
+
+| Metric             | Original baseline | W5 head | W5 delta |
+| ------------------ | ----------------: | ------: | -------: |
+| Raw JavaScript     |          2.48 MB | 2.49 MB | +8.2 kB  |
+| Gzipped JavaScript |         835.0 kB | 831.2 kB | -3.9 kB |
+| npm tarball        |         958.5 kB | 959.6 kB | +1.1 kB |
+| npm unpacked       |          3.32 MB | 3.33 MB | +9.0 kB  |
+
+At source level, the moved Android production tree accounts for 456,492 B removed from
+`src/platforms/android` versus 475,413 B in changed package targets, a +18,921 B relocation
+delta; the new root host/facade seam adds 19,978 B. The published +9.0 kB unpacked result is the
+package result, not a source-byte estimate. The increase is attributable to the named `mechanics`
+closure, the injected root host composition, and preserving deferred helper loading while root
+chunks are removed or repartitioned. The largest packed increase is the mechanics chunk; it is
+offset by deletion or shrinkage of the superseded root Android chunks.
+
+A smaller design that retained root re-export shims, a broad barrel, or ambient filesystem/process
+access would reduce gross source movement but violate this ADR's package-closure,
+no-compatibility-shim, named-facet, host-injection, and implementation-lazy constraints. This is
+exceptional W5 accounting, not reusable checkpoint headroom; after rebasing on #2116, the
+combined-family CI size result remains the authoritative current measurement.
+
 Raw per-unit parity, planted-red, and size evidence belongs in #1739 and its PRs; this ADR retains
 the decision, the evidence tiers, and the rule that each unit must justify exceptional growth
 without treating checkpoint budget as an allowance.

packages/platform-android/src/adb-host.ts

@@ -12,11 +12,6 @@ import type {
   AndroidAdbSpawnOptions,
 } from './adb-transport.ts';
 
-// R13 bars platform packages from raw process, fs, and ambient host authority; the adb/IME
-// cluster reaches those primitives only through this explicitly injected host port. The root
-// composition wiring (src/platform-runtime-android-adb-host.ts) binds it before any consumer
-// can call into the cluster.
-
 export type AndroidAdbCommandExecutorOverride = (
   cmd: string,
   args: string[],

scripts/check-affected/model.test.ts

@@ -123,6 +123,25 @@ test('Android helper change selects the android-helpers build', () => {
   ]);
 });
 
+test('Android package test fixture selects the unit suite instead of failing open', () => {
+  const fixture =
+    'packages/platform-android/src/__tests__/test-utils/fixtures/android-helper-apk.fixture';
+  const result = plan([fixture]);
+  assert.equal(result.failOpen, false);
+  assert.deepEqual(result.checks, ['unit']);
+  assert.deepEqual(
+    result.reasons.filter((reason) => reason.rule === 'own:android-package-test-fixture'),
+    [
+      {
+        check: 'unit',
+        path: fixture,
+        rule: 'own:android-package-test-fixture',
+        detail: 'the Android package test fixture is consumed by the unit suite',
+      },
+    ],
+  );
+});
+
 test('MCP metadata change selects the mcp-metadata check', () => {
   assert.deepEqual(ids(['server.json']), ['mcp-metadata']);
 });

scripts/check-affected/model.ts

@@ -481,6 +481,14 @@ const BUILD_OWNERSHIP: ReadonlyArray<{
     owns: (file) =>
       file.startsWith('android/snapshot-helper/') || file.startsWith('android/ime-helper/'),
   },
+  {
+    check: 'unit',
+    rule: 'own:android-package-test-fixture',
+    detail: 'the Android package test fixture is consumed by the unit suite',
+    owns: (file) =>
+      file ===
+      'packages/platform-android/src/__tests__/test-utils/fixtures/android-helper-apk.fixture',
+  },
   {
     check: 'macos-helper',
     rule: 'own:macos-helper',

scripts/layering/platform-package-policy.ts

@@ -60,10 +60,9 @@ export function checkPlatformsRootShape(files: readonly string[]): LayeringViola
       rule: 'platforms-root-shape',
       file,
       line: 1,
-      message:
-        file.startsWith('src/platforms/android/')
-          ? 'the Android family has moved to packages/platform-android; remove the superseded src/platforms/android path'
-          : 'src/platforms may hold only the remaining apple family directory and __tests__; retired family code belongs in its platform package and shared code belongs in a substrate package',
+      message: file.startsWith('src/platforms/android/')
+        ? 'the Android family has moved to packages/platform-android; remove the superseded src/platforms/android path'
+        : 'src/platforms may hold only the remaining apple family directory and __tests__; retired family code belongs in its platform package and shared code belongs in a substrate package',
     }));
 }
 const APPLE_RUNNER_FACADE = '@agent-device/platform-apple/runner';

src/daemon/__tests__/request-platform-providers.test.ts

@@ -18,7 +18,7 @@ import {
   runXcrun,
 } from '../../platforms/apple/core/tool-provider.ts';
 import type { AndroidAdbExecutor } from '@agent-device/platform-android/mechanics';
-import { resolveWebProvider, type WebProvider } from '../../platforms/web/provider.ts';
+import { resolveWebProvider, type WebProvider } from '@agent-device/platform-web';
 import {
   resolveAppleRunnerScreenRecordingTransport,
   type AppleRunnerScreenRecordingTransport,

src/platform-runtime-android-adb-host.ts

@@ -25,8 +25,6 @@ import {
 import os from 'node:os';
 import path from 'node:path';
 
-// Composition wiring for the extracted Android family: the package owns transport and IME
-// semantics; this file injects the raw host primitives R13 bars from platform packages.
 bindAndroidAdbHost({
   environment: process.env,
   files: {
@@ -70,7 +68,6 @@ bindAndroidAdbHost({
           directoryHandle = await open(directory, 'r');
           await directoryHandle.sync();
         } catch {
-          // Atomic rename remains the correctness boundary where directory sync is unavailable.
         } finally {
           if (directoryHandle) await directoryHandle.close().catch(() => {});
         }
@@ -82,15 +79,10 @@ bindAndroidAdbHost({
     writeBytes: async (filePath, value) => await writeFile(filePath, value),
   },
   execSerialAdb: async (serial, args, options) =>
-    // Local adb execution must escape any active provider scope to avoid routing
-    // tunnel-backed providers back into themselves when they shell out to adb.
     await withoutCommandExecutorOverride(
       async () =>
         await runCmd('adb', ['-s', serial, ...args], {
           ...options,
-          // Some `adb shell` children can survive killing the adb parent and keep
-          // requests open past timeout. Give each adb call its own process group
-          // so timeout/abort cleanup can tear down the whole local command tree.
           detached: process.platform !== 'win32',
         }),
     ),