diff --git a/docs/implplan/SPRINT_20260309_002_FE_live_frontdoor_canonical_route_sweep.md b/docs/implplan/SPRINT_20260309_002_FE_live_frontdoor_canonical_route_sweep.md
index 5a4d84d73..4254ed988 100644
--- a/docs/implplan/SPRINT_20260309_002_FE_live_frontdoor_canonical_route_sweep.md
+++ b/docs/implplan/SPRINT_20260309_002_FE_live_frontdoor_canonical_route_sweep.md
@@ -70,6 +70,7 @@ Completion criteria:
 | 2026-03-09 | After the full image rebuild and the next web-only repair pass, reran the authenticated 111-route sweep. The live backlog moved to 24 failing routes, with the earlier title regressions and feeds-airgap issue cleared while new backend/runtime failures remained concentrated in analytics, JobEngine, integrations, policy governance, notifications, and trust authorization. | Developer |
 | 2026-03-10 | Full rebuild and redeploy completed cleanly, but the deeper live `ops/policy` action sweep stalled after authentication without writing a result file. This iteration is hardening the sweep itself with per-action watchdogs, progress persistence, and explicit failure semantics so the next scratch loops do not burn hours on a silent Playwright hang. | Developer |
 | 2026-03-10 | Completed the hardening pass on `live-ops-policy-action-sweep.mjs`: the script now persists progress while it runs, reports blocked actions with step-level snapshots, and exits non-zero on action/runtime failures. After the policy frontdoor fix, the same sweep completed cleanly on the rebuilt stack with zero runtime issues. | Developer |
+| 2026-03-10 | Hardened `live-frontdoor-auth.mjs` so it waits for a real authority transition or established shell session before declaring authentication complete. This prevents false-positive sign-in clicks on rebuilt stacks where the login form appears asynchronously or the welcome page lingers after the CTA. | Developer |
 
 ## Decisions & Risks
 - Decision: keep this sprint focused on broad route-level live verification and action inventory, not on fixing specific route defects before the rebuilt stack is actually exercised.
@@ -78,6 +79,7 @@ Completion criteria:
 - Decision: treat documented/canonical redirects as valid route outcomes in the live sweep (`/releases`, `/releases/promotion-queue`, `/ops/policy`, `/ops/policy/audit`, `/ops/platform-setup/trust-signing`, `/setup/topology`) because those aliases are intentional product behavior, not regressions.
 - Risk: many remaining failures are real frontdoor contract mismatches rather than simple UI copy/render issues, so the next iterations need backend/frontend contract inspection, not just surface-level error-banner suppression.
 - Decision: the deep live sweeps must be self-diagnosing. A hanging Playwright command is a harness defect because it blocks the problem-first loop from collecting the full issue set.
+- Decision: authentication success in the live harness is defined by an established Stella Ops session or a completed authority redirect, not by a single successful CTA click on `/welcome`.
 
 ## Next Checkpoints
 - 2026-03-09: land the reusable live canonical route sweep script.
diff --git a/src/Web/StellaOps.Web/scripts/live-frontdoor-auth.mjs b/src/Web/StellaOps.Web/scripts/live-frontdoor-auth.mjs
index aef63862f..1439a23e8 100644
--- a/src/Web/StellaOps.Web/scripts/live-frontdoor-auth.mjs
+++ b/src/Web/StellaOps.Web/scripts/live-frontdoor-auth.mjs
@@ -59,6 +59,20 @@ async function waitForShell(page) {
   ]);
 }
 
+async function waitForAuthTransition(page, usernameField, passwordField, timeoutMs = 10_000) {
+  await Promise.race([
+    page.waitForURL((url) => url.toString().includes('/connect/authorize') || url.toString().includes('/auth/callback'), {
+      timeout: timeoutMs,
+    }).catch(() => {}),
+    usernameField.waitFor({ state: 'visible', timeout: timeoutMs }).catch(() => {}),
+    passwordField.waitFor({ state: 'visible', timeout: timeoutMs }).catch(() => {}),
+    page.waitForFunction(() => Boolean(sessionStorage.getItem('stellaops.auth.session.full')), null, {
+      timeout: timeoutMs,
+    }).catch(() => {}),
+    page.waitForTimeout(timeoutMs),
+  ]);
+}
+
 export async function authenticateFrontdoor(options = {}) {
   const baseUrl = options.baseUrl?.trim() || DEFAULT_BASE_URL;
   const username = options.username?.trim() || DEFAULT_USERNAME;
@@ -134,9 +148,6 @@ export async function authenticateFrontdoor(options = {}) {
     'button.cta',
   ]);
 
-  await clickIfVisible(signInTrigger);
-  await page.waitForTimeout(1_500);
-
   const usernameField = createLocator(page, [
     'input[name="username"]',
     'input[name="Username"]',
@@ -149,6 +160,13 @@ export async function authenticateFrontdoor(options = {}) {
     'input[type="password"]',
   ]);
 
+  const signInClicked = await clickIfVisible(signInTrigger);
+  if (signInClicked) {
+    await waitForAuthTransition(page, usernameField, passwordField);
+  } else {
+    await page.waitForTimeout(1_500);
+  }
+
   const hasLoginForm = (await usernameField.count()) > 0 && (await passwordField.count()) > 0;
   if (page.url().includes('/connect/authorize') || hasLoginForm) {
     const filledUser = await fillIfVisible(usernameField, username);
@@ -168,15 +186,31 @@ export async function authenticateFrontdoor(options = {}) {
 
     await submitButton.click({ timeout: 10_000 });
 
-    await page.waitForURL(
-      (url) => !url.toString().includes('/connect/authorize') && !url.toString().includes('/auth/callback'),
-      { timeout: 30_000 },
-    ).catch(() => {});
+    await Promise.race([
+      page.waitForURL(
+        (url) => !url.toString().includes('/connect/authorize') && !url.toString().includes('/auth/callback'),
+        { timeout: 30_000 },
+      ).catch(() => {}),
+      page.waitForFunction(() => Boolean(sessionStorage.getItem('stellaops.auth.session.full')), null, {
+        timeout: 30_000,
+      }).catch(() => {}),
+    ]);
   }
 
   await waitForShell(page);
   await page.waitForTimeout(2_500);
 
+  const sessionStatus = await page.evaluate(() => ({
+    hasFullSession: Boolean(sessionStorage.getItem('stellaops.auth.session.full')),
+    hasSessionInfo: Boolean(sessionStorage.getItem('stellaops.auth.session.info')),
+  }));
+  const signInStillVisible = await signInTrigger.isVisible().catch(() => false);
+  if (!sessionStatus.hasFullSession || (!page.url().includes('/connect/authorize') && signInStillVisible)) {
+    throw new Error(
+      `Frontdoor authentication did not establish a Stella Ops session. finalUrl=${page.url()} signInVisible=${signInStillVisible}`,
+    );
+  }
+
   await context.storageState({ path: statePath });
 
   const report = {