diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 375bc9077..491f2468d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -150,7 +150,7 @@ jobs:
         run: npm run check:boundaries
 
       - name: Run focused onboarding tests
-        run: node --test src/setupDoctor.test.mjs src/pinokioEnvironment.test.mjs src/pinokioPreflight.test.mjs src/pinokioLauncherContract.test.mjs src/keySetupHardening.test.mjs src/mapStartup.test.mjs src/hudSummaryResponse.test.mjs
+        run: node --test src/setupDoctor.test.mjs src/pinokioEnvironment.test.mjs src/pinokioPreflight.test.mjs src/pinokioLauncherContract.test.mjs src/keySetupHardening.test.mjs src/mapStartup.test.mjs src/hudSummaryResponse.test.mjs src/codexOauthRealtime.test.mjs
 
       - name: Build production bundle
         run: npm run build
diff --git a/scripts/run-unit-tests.mjs b/scripts/run-unit-tests.mjs
index 9bd7e70e0..6cc6aaa94 100644
--- a/scripts/run-unit-tests.mjs
+++ b/scripts/run-unit-tests.mjs
@@ -21,9 +21,20 @@ export function assertNode24AllocationRuntime(version = process.versions.node) {
   return version;
 }
 
+/**
+ * Directories this runner searches for `*.test.mjs`, in stable order.
+ *
+ * `server/` belongs here because provider modules own tests of their own: a
+ * suite placed beside the module it covers must run, and CI's unit-test job runs
+ * `npm test`, so a directory missing from this list is a suite that never runs
+ * there. `unitTestRunner.test.mjs` asserts the list covers every `*.test.mjs`
+ * outside dependencies, build output and dot-directories, so adding a tree
+ * without adding it here fails.
+ */
+export const UNIT_TEST_ROOTS = Object.freeze(['src', 'server']);
+
 /** Discover repository unit tests in stable path order. */
 export function discoverUnitTestFiles(root = process.cwd()) {
-  const sourceRoot = path.join(root, 'src');
   const files = [];
   const visit = (directory) => {
     for (const entry of readdirSync(directory, { withFileTypes: true })) {
@@ -34,7 +45,7 @@ export function discoverUnitTestFiles(root = process.cwd()) {
       }
     }
   };
-  visit(sourceRoot);
+  for (const testRoot of UNIT_TEST_ROOTS) visit(path.join(root, testRoot));
   return files.sort();
 }
 
diff --git a/src/codexOauthRealtime.test.mjs b/src/codexOauthRealtime.test.mjs
index 07e1a7dcc..4a577ac70 100644
--- a/src/codexOauthRealtime.test.mjs
+++ b/src/codexOauthRealtime.test.mjs
@@ -145,17 +145,20 @@ test('Codex OAuth reader enforces expiry margin and bounds tokens without exp by
 
 test('Codex login resolves an installed executable before PATH and starts browser auth detached', async () => {
   const checked = [];
+  // Built with path.join so the stub matches the resolver on Windows too,
+  // where the separators are backslashes.
+  const installed = path.join('/home/fixture', '.local', 'bin', 'codex');
   assert.equal(
     resolveCodexExecutable({
       environment: {},
       home: '/home/fixture',
       access(candidate) {
         checked.push(candidate);
-        if (candidate.endsWith('/.local/bin/codex')) return;
+        if (candidate === installed) return;
         throw new Error('missing');
       },
     }),
-    path.join('/home/fixture', '.local', 'bin', 'codex'),
+    installed,
   );
   assert.equal(checked.length, 1);
 
diff --git a/src/unitTestRunner.test.mjs b/src/unitTestRunner.test.mjs
index 002dcb796..80d9091e0 100644
--- a/src/unitTestRunner.test.mjs
+++ b/src/unitTestRunner.test.mjs
@@ -1,14 +1,40 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { readFileSync } from 'node:fs';
+import { readFileSync, readdirSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
 import {
   ALLOCATION_TEST_FILES,
+  UNIT_TEST_ROOTS,
   allocationTestArgs,
   assertNode24AllocationRuntime,
   buildUnitTestPlan,
+  discoverUnitTestFiles,
   isCalibratedAllocationRuntime,
 } from '../scripts/run-unit-tests.mjs';
 
+const repositoryRoot = fileURLToPath(new URL('..', import.meta.url));
+
+/** Every `*.test.mjs` a contributor could add, found without consulting the runner. */
+function testFilesOnDisk(root) {
+  // Build outputs and dependencies are not places a contributor writes a test,
+  // and walking them would be slow enough to matter. Everything else counts.
+  const skip = new Set(['node_modules', 'dist', 'build', 'public']);
+  const found = [];
+  const visit = (directory) => {
+    for (const entry of readdirSync(directory, { withFileTypes: true })) {
+      if (entry.name.startsWith('.') || skip.has(entry.name)) continue;
+      const absolute = path.join(directory, entry.name);
+      if (entry.isDirectory()) visit(absolute);
+      else if (entry.isFile() && entry.name.endsWith('.test.mjs')) {
+        found.push(path.relative(root, absolute).split(path.sep).join('/'));
+      }
+    }
+  };
+  visit(root);
+  return found.sort();
+}
+
 test('unit runner serializes only GC-bracketed allocation microbenchmarks', () => {
   const ordinary = [
     'src/data/manager.test.mjs',
@@ -37,6 +63,30 @@ test('unit runner serializes only GC-bracketed allocation microbenchmarks', () =
   );
 });
 
+test('the runner discovers every test file in the repository', () => {
+  // CI's unit-test job runs `npm test`, which runs exactly what this function
+  // returns. A `*.test.mjs` outside the searched roots therefore never runs
+  // there, while still reading — in review and to its author — like covered
+  // code. Compare the two sets rather than their sizes, so the failure names the
+  // files instead of only disagreeing about a count. The final equality also
+  // catches the reverse: files the runner finds that this walk skips.
+  const discovered = discoverUnitTestFiles(repositoryRoot);
+  const onDisk = testFilesOnDisk(repositoryRoot);
+  const undiscovered = onDisk.filter((file) => !discovered.includes(file));
+  assert.deepEqual(
+    undiscovered,
+    [],
+    `test files the runner never executes: ${undiscovered.join(', ')}`,
+  );
+  assert.deepEqual(discovered, onDisk);
+  for (const file of discovered) {
+    assert.ok(
+      UNIT_TEST_ROOTS.some((root) => file.startsWith(`${root}/`)),
+      `${file} should sit under one of ${UNIT_TEST_ROOTS.join(', ')}`,
+    );
+  }
+});
+
 test('allocation runtime calibration is explicit and pinned to Node 24', () => {
   assert.equal(assertNode24AllocationRuntime('24.19.0'), '24.19.0');
   assert.throws(