diff --git a/services/platform/backend/integration-check.ts b/services/platform/backend/integration-check.ts
index 90377e8227..bec1726ec9 100644
--- a/services/platform/backend/integration-check.ts
+++ b/services/platform/backend/integration-check.ts
@@ -31757,17 +31757,54 @@ async function checkTwoFactor(
   // port kept only the failure half, so an attacker who registered their own
   // passkey and turned TOTP off left no trace at all. Action names are 0.4's
   // verbatim — a rename would break any saved query grouping on them.
+  //
+  // A DEDICATED user, not the harness's own. This block enables 2FA,
+  // regenerates backup codes, disables it, and registers and removes a
+  // passkey — so running it on the shared session leaves that user's
+  // second-factor state changed and invalidates their session. Five later
+  // checks failed that way: the 2FA grace check, and four chat checks that
+  // need a live session.
+  const lifecycleSignUp = await fetch(`${base}/api/auth/sign-up/email`, {
+    method: 'POST',
+    headers: { 'content-type': 'application/json', origin: base },
+    body: JSON.stringify({
+      email: `itest-2fa-lifecycle-${ctx.orgId.slice(0, 8)}@door.test`,
+      password: 'itest-password-1',
+      name: 'Lifecycle',
+    }),
+  });
+  const lifecycleCookie = cookieHeaderFrom(lifecycleSignUp);
+  const lifecycleUser = z
+    .object({ user: z.object({ id: z.string() }) })
+    .loose()
+    .safeParse(await lifecycleSignUp.json());
+  const lifecycleUserId = lifecycleUser.success
+    ? lifecycleUser.data.user.id
+    : '';
+  // Audit rows are org-scoped, so the lifecycle user needs a membership or
+  // their events have no org to land under and the trail reads empty.
+  await sql`
+    INSERT INTO "member" ("id", "organizationId", "userId", "role",
+                          "createdAt")
+    VALUES (${`m-2fa-${lifecycleUserId}`}, ${ctx.orgId}, ${lifecycleUserId},
+            'member', ${new Date()})
+    ON CONFLICT ("id") DO NOTHING
+  `;
   const authPost = (route: string, body: unknown): Promise<Response> =>
     fetch(`${base}/api/auth${route}`, {
       method: 'POST',
-      headers: { 'content-type': 'application/json', cookie, origin: base },
+      headers: {
+        'content-type': 'application/json',
+        cookie: lifecycleCookie,
+        origin: base,
+      },
       body: JSON.stringify(body),
     });
   const lifecycleActions = async (): Promise<string[]> => {
     const rows = await sql<{ action: string }[]>`
       SELECT action FROM app.audit_logs
       WHERE org_id = ${ctx.orgId} AND resource_type = 'twoFactorAuth'
-        AND resource_id = ${userId}
+        AND resource_id = ${lifecycleUserId}
       ORDER BY ts ASC
     `;
     return rows.map((row) => row.action);
@@ -31796,7 +31833,7 @@ async function checkTwoFactor(
     SELECT category, status,
            (metadata->>'backupCodesRegenerated')::boolean AS regenerated
     FROM app.audit_logs
-    WHERE org_id = ${ctx.orgId} AND resource_id = ${userId}
+    WHERE org_id = ${ctx.orgId} AND resource_id = ${lifecycleUserId}
       AND action = '2fa_enrolled' AND metadata ? 'backupCodesRegenerated'
     ORDER BY ts DESC LIMIT 1
   `;
@@ -31816,7 +31853,7 @@ async function checkTwoFactor(
     'passkey_removed',
   ] as const) {
     await recordTwoFactorLifecycleEvent(sql, {
-      userId,
+      userId: lifecycleUserId,
       action,
       actorEmail: email,
       ip: '203.0.113.9',
@@ -31828,11 +31865,12 @@ async function checkTwoFactor(
   const shapes = await sql<{ category: string; status: string }[]>`
     SELECT DISTINCT category, status FROM app.audit_logs
     WHERE org_id = ${ctx.orgId} AND resource_type = 'twoFactorAuth'
-      AND resource_id = ${userId}
+      AND resource_id = ${lifecycleUserId}
   `;
-  // Leave 2FA OFF: later lanes sign this account in with password alone.
+  // The dedicated user ends with 2FA off, which is also what the assertion
+  // below reads — no later lane touches this account either way.
   const enrolled = await sql<{ enabled: boolean | null }[]>`
-    SELECT "twoFactorEnabled" AS enabled FROM "user" WHERE "id" = ${userId}
+    SELECT "twoFactorEnabled" AS enabled FROM "user" WHERE "id" = ${lifecycleUserId}
   `;
   record(
     'two-factor: successful lifecycle events audit (#1508 action names)',