diff --git a/config/scripts/patched-dependencies-frozen-install.test.mjs b/config/scripts/patched-dependencies-frozen-install.test.mjs
index f24c04e227f..76e20d47229 100644
--- a/config/scripts/patched-dependencies-frozen-install.test.mjs
+++ b/config/scripts/patched-dependencies-frozen-install.test.mjs
@@ -1,4 +1,12 @@
-import { cpSync, copyFileSync, existsSync, mkdirSync, mkdtempSync } from 'node:fs'
+import {
+  cpSync,
+  copyFileSync,
+  existsSync,
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  writeFileSync
+} from 'node:fs'
 import { tmpdir } from 'node:os'
 import { delimiter, join, resolve } from 'node:path'
 import { describe, expect, it } from 'vitest'
@@ -20,6 +28,7 @@ import { removeTreeSync } from '../../src/shared/windows-transient-lock-removal.
  * with no node_modules and no native builds.
  */
 const PROJECT_DIR = resolve(import.meta.dirname, '../..')
+const WINDOWS_PROCESS_TREE_PATCH = '@vscode__windows-process-tree@0.8.0.patch'
 
 /** runProcessSync wants an absolute program on Windows, where pnpm is a `.cmd` shim. */
 function resolvePnpmProgram() {
@@ -63,5 +72,73 @@ describe('patched dependencies', () => {
     } finally {
       removeTreeSync(scratch)
     }
-  })
+    // The 300s spawn budget is only reachable if the case is allowed to take it;
+    // config/vitest.config.ts caps every case at 30s by default.
+  }, 300_000)
+
+  /**
+   * `--lockfile-only` resolves; it never applies a patch. So the case above is
+   * bounded to hash consistency, and the actual question -- can pnpm still put
+   * the patched reader on disk? -- had nothing covering it.
+   *
+   * One package, patch applied for real, assert the marker landed. Scoped to the
+   * single dependency so it stays a ~2s check rather than a full install.
+   */
+  it('materializes the patched command-line reader on a real install', () => {
+    const pnpm = resolvePnpmProgram()
+    expect(pnpm, 'pnpm must be on PATH; it is the only thing that can check this').not.toBeNull()
+
+    const scratch = mkdtempSync(join(tmpdir(), 'orca-patch-apply-'))
+    try {
+      mkdirSync(join(scratch, 'config', 'patches'), { recursive: true })
+      copyFileSync(
+        join(PROJECT_DIR, 'config', 'patches', WINDOWS_PROCESS_TREE_PATCH),
+        join(scratch, 'config', 'patches', WINDOWS_PROCESS_TREE_PATCH)
+      )
+      writeFileSync(
+        join(scratch, 'package.json'),
+        `${JSON.stringify(
+          {
+            name: 'orca-patch-apply-probe',
+            version: '1.0.0',
+            dependencies: { '@vscode/windows-process-tree': '0.8.0' }
+          },
+          null,
+          2
+        )}\n`
+      )
+      writeFileSync(
+        join(scratch, 'pnpm-workspace.yaml'),
+        'packages: []\n' +
+          'patchedDependencies:\n' +
+          `  '@vscode/windows-process-tree@0.8.0': config/patches/${WINDOWS_PROCESS_TREE_PATCH}\n`
+      )
+
+      const result = runProcessSync({
+        program: pnpm,
+        args: ['install', '--no-frozen-lockfile', '--ignore-scripts'],
+        cwd: scratch,
+        timeoutMs: 300_000
+      })
+      expect(result.code, `${result.stdout}\n${result.stderr}`).toBe(0)
+
+      const materialized = readFileSync(
+        join(
+          scratch,
+          'node_modules',
+          '@vscode',
+          'windows-process-tree',
+          'src',
+          'process_commandline.cc'
+        ),
+        'utf8'
+      )
+      expect(materialized).toContain('kProcessCommandLineInformation')
+      // The whole point of the patch: the upstream reader is gone, not merely
+      // supplemented.
+      expect(materialized).not.toContain('ReadProcessMemory')
+    } finally {
+      removeTreeSync(scratch)
+    }
+  }, 300_000)
 })
diff --git a/config/scripts/rebuild-native-deps-node-pty.test.mjs b/config/scripts/rebuild-native-deps-node-pty.test.mjs
index 27594f2a663..871732dd53d 100644
--- a/config/scripts/rebuild-native-deps-node-pty.test.mjs
+++ b/config/scripts/rebuild-native-deps-node-pty.test.mjs
@@ -344,4 +344,37 @@ describe('rebuild-native-deps patched node-pty rebuild', () => {
       }
     }
   )
+
+  // The binary this step produces is the one copied into the packaged app. The
+  // relay build checks its own artifact and ensure-native-runtime checks what it
+  // loads; nothing checked this one, so a rebuild that quietly emitted the
+  // upstream reader shipped. Both non-clean states have to fail, which is the
+  // caller the tri-state was missing: after a rebuild that reported success, an
+  // absent binary is a broken build, not an absence to shrug at.
+  for (const [addon, expected] of [
+    ['unpatched', 'still imports ReadProcessMemory'],
+    ['none', 'is not there']
+  ]) {
+    it(`fails a Windows rebuild that leaves ${addon} windows-process-tree bytes`, () => {
+      const projectDir = mkTempProject()
+
+      try {
+        writeFakeUsableElectronPackage(projectDir, { platform: 'win32' })
+        writeFakeElectronRebuild(projectDir, { addon })
+        writeFakeNodePtyConptyPayload(projectDir, 'x64')
+        writeFakeWindowsProcessTreeWithNodeAddonApi(projectDir)
+
+        const result = runRebuildScript(
+          projectDir,
+          { npm_config_platform: 'win32', npm_config_arch: 'x64' },
+          ['--platform=win32', '--arch=x64', '--force']
+        )
+
+        expect(result.status).not.toBe(0)
+        expect(result.stderr).toContain(expected)
+      } finally {
+        removeTreeSync(projectDir)
+      }
+    })
+  }
 })
diff --git a/config/scripts/rebuild-native-deps-test-fixtures.mjs b/config/scripts/rebuild-native-deps-test-fixtures.mjs
index cdc204f210c..2cb7d8ba8b4 100644
--- a/config/scripts/rebuild-native-deps-test-fixtures.mjs
+++ b/config/scripts/rebuild-native-deps-test-fixtures.mjs
@@ -212,17 +212,46 @@ if (${JSON.stringify(createExecutable)}) {
   )
 }
 
-export function writeFakeElectronRebuild(projectDir, { logPathEnv = null } = {}) {
+/** Bytes that stand in for a compiled addon's import table. */
+const FAKE_ADDON_BYTES = {
+  clean: 'MZ\0ntdll.dll\0NtQueryInformationProcess\0',
+  unpatched: 'MZ\0KERNEL32.dll\0ReadProcessMemory\0'
+}
+
+/**
+ * A rebuild that produces nothing leaves no addon to inspect, and the script now
+ * asserts the binary it just built is a patched one. Emit a stand-in so the
+ * fixture models a rebuild that actually succeeded. `addon` picks which kind,
+ * because "produced the upstream reader" and "produced nothing" are both real
+ * outcomes that assertion has to tell apart.
+ */
+export function writeFakeElectronRebuild(projectDir, { logPathEnv = null, addon = 'clean' } = {}) {
   const rebuildDir = join(projectDir, 'node_modules', '@electron', 'rebuild')
   mkdirSync(rebuildDir, { recursive: true })
   writeFileSync(join(rebuildDir, 'package.json'), JSON.stringify({ type: 'module' }))
+  const emitAddon =
+    addon === 'none'
+      ? ''
+      : `
+  const packageDir = join('node_modules', '@vscode', 'windows-process-tree')
+  if (existsSync(join(packageDir, 'package.json'))) {
+    mkdirSync(join(packageDir, 'build', 'Release'), { recursive: true })
+    writeFileSync(
+      join(packageDir, 'build', 'Release', 'windows_process_tree.node'),
+      ${JSON.stringify(FAKE_ADDON_BYTES[addon])}
+    )
+  }`
+  const emitImports =
+    addon === 'none'
+      ? ''
+      : "import { existsSync, mkdirSync, writeFileSync } from 'node:fs'\nimport { join } from 'node:path'\n"
   writeFileSync(
     join(rebuildDir, 'index.js'),
     logPathEnv
       ? `
 import { appendFileSync } from 'node:fs'
-
-export async function rebuild(options) {
+${emitImports}
+export async function rebuild(options) {${emitAddon}
   const logPath = process.env[${JSON.stringify(logPathEnv)}]
   if (!logPath) {
     return
@@ -240,7 +269,10 @@ export async function rebuild(options) {
   )
 }
 `
-      : 'export async function rebuild() {}\n'
+      : `${emitImports}
+export async function rebuild() {${emitAddon}
+}
+`
   )
 }
 
diff --git a/config/scripts/rebuild-native-deps.mjs b/config/scripts/rebuild-native-deps.mjs
index be2d239916e..863aac850a1 100644
--- a/config/scripts/rebuild-native-deps.mjs
+++ b/config/scripts/rebuild-native-deps.mjs
@@ -22,7 +22,9 @@ import { rebuild } from '@electron/rebuild'
 import { execFileSync, spawnSync } from 'node:child_process'
 import {
   ensureWindowsProcessTreeCommandLinePatch,
-  stageWindowsProcessTreeNodeAddonApiHeaders
+  inspectWindowsProcessTreeAddon,
+  stageWindowsProcessTreeNodeAddonApiHeaders,
+  windowsProcessTreeAddonPath
 } from './windows-process-tree-gyp-rebuild.mjs'
 import {
   copyFileSync,
@@ -174,6 +176,7 @@ try {
     force: true
   })
   restoreNodePtyWindowsConptyRuntime()
+  assertWindowsProcessTreeAddonIsPatched()
 } catch (/** @type {any} */ err) {
   console.error('[rebuild] Native module rebuild failed:', err?.message ?? err)
   if (isWindowsNativeLockError(err)) {
@@ -193,6 +196,40 @@ try {
   process.exit(1)
 }
 
+/**
+ * The binary this rebuild just produced is the one the packaged app ships.
+ *
+ * The relay build asserts its own artifact and `ensure-native-runtime.mjs`
+ * asserts what it loads, but nothing checked the addon that gets copied into the
+ * packaged `node_modules` -- so a rebuild that silently produced the upstream
+ * reader would reach users. Anything but `clean` fails: after a rebuild that
+ * reported success the binary must exist, so `missing` is a broken build, not an
+ * absence to shrug at. This is the caller that needs the state to be a state and
+ * not a boolean.
+ */
+function assertWindowsProcessTreeAddonIsPatched() {
+  if (
+    rebuildPlatform !== 'win32' ||
+    !modulesToRebuild.includes('@vscode/windows-process-tree') ||
+    !existsSync(join(projectDir, 'node_modules', '@vscode', 'windows-process-tree', 'package.json'))
+  ) {
+    return
+  }
+  const addonPath = windowsProcessTreeAddonPath()
+  const state = inspectWindowsProcessTreeAddon(addonPath)
+  if (state === 'clean') {
+    return
+  }
+  throw new Error(
+    state === 'missing'
+      ? `the rebuild reported success but ${addonPath} is not there, so the packaged app would ` +
+          'ship no windows-process-tree addon at all.'
+      : `${addonPath} still imports ReadProcessMemory, so it was not built from the patched ` +
+          'command-line reader. The packaged app would carry the primitive MDE scores as ' +
+          'credential dumping.'
+  )
+}
+
 function restoreNodePtyWindowsConptyRuntime() {
   if (rebuildPlatform !== 'win32' || !onlyModules.includes('node-pty')) {
     return