feat(GRO-2359): route Authentik new-SSO users into OOBE (web)

The post-auth handler in CustomerPortal previously rendered the
"Portal access not configured" card when the SSO bridge returned 404
(no client row for the user's email). That trapped first-time SSO
users on a dead-end screen with no path to portal creation.

This change routes the 404 to a new OOBE component (src/portal/OOBE.tsx)
that drives portal creation:
  * Mounts inline inside CustomerPortal so the post-auth flow stays
    inside the portal render tree (no App-level router needed).
  * Also reachable as a direct deep-link via the new /onboarding route
    in App.tsx (for grooming admins or recovery flows).
  * Submits to a new POST /api/portal/clients-from-auth endpoint in
    groombook-api (companion commit) that creates a fresh client row
    bound to the Better Auth email. 409 means the email already has a
    portal record — the OOBE shows a portal-selection message.
  * Uses the canonical shared signOut() from lib/auth-client (GRO-2358
    invariant) for the Sign out button.
  * Full window.location.href reload on submit success to reset the
    bridge's cached state and land the user in their portal.

The no-access card itself is preserved for the deep-link deleted-portal
case (a customer whose portal was disabled/deleted), signalled via
?noAccess=deleted-portal on a portal sub-route. The OOBE handles the
first-time-creation case; the no-access card handles the "had a portal
but lost it" case.

Test coverage:
  * "routes to /onboarding when session-from-auth returns 404 (GRO-2359)"
    — proves the post-auth 404 mounts the OOBE inline, not the legacy
    no-access card.
  * 6 new OOBE tests: render from direct link, name prefill, form
    submission, 409 portal-selection, required-name validation, shared
    signOut(), redirect on no-session.
  * P1 no-access tests reworked to use ?noAccess=deleted-portal so the
    GRO-2358 signOut invariant is still verified on the only surviving
    path to the no-access card.

UAT_PLAYBOOK §5.25.5–6e rewritten to cover the OOBE flow (form submit,
409, deep-link mount, deleted-portal no-access card).

Paired with the api PR on feature/2357-p2-portal-clients-from-auth.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/portal/CustomerPortal.tsx

@@ -13,6 +13,7 @@ import { Communication } from "./sections/Communication.js";
 import { AccountSettings } from "./sections/AccountSettings.js";
 import { ImpersonationBanner } from "./ImpersonationBanner.js";
 import { AuditLogViewer } from "./AuditLogViewer.js";
+import { OOBE } from "./OOBE.js";
 import { useBranding } from "../BrandingContext.js";
 import { getDevUser } from "../pages/DevLoginSelector.js";
 import { signOut } from "../lib/auth-client.js";
@@ -53,6 +54,13 @@ export function CustomerPortal() {
   // (e.g. authenticated user with no matching client row). Rendered in place
   // of the portal chrome instead of bouncing back to /login.
   const [authError, setAuthError] = useState<string | null>(null);
+  // GRO-2359 — the SSO bridge 404 (no client row for the user's email)
+  // routes the user into the OOBE. We mount the OOBE inline rather than
+  // navigating to /onboarding so the post-auth flow stays inside the
+  // CustomerPortal render tree (test-isolated, no App-level router needed
+  // for the integration to work). The /onboarding route in App.tsx is
+  // still the mount point for direct deep-links to the same component.
+  const [showOOBE, setShowOOBE] = useState(false);
   const { branding } = useBranding();
   const [searchParams, setSearchParams] = useSearchParams();
 
@@ -63,6 +71,18 @@ export function CustomerPortal() {
     initDone.current = true;
 
     const sessionId = searchParams.get("sessionId");
+    // GRO-2359: a deep-link to a portal sub-route with ?noAccess=deleted-portal
+    // is the only path that still shows the no-access card. The post-auth
+    // 404-from-bridge path now navigates to /onboarding (OOBE) so the new
+    // user can create a portal. The deleted-portal case is set explicitly
+    // (e.g. a groomer who disabled a client) and uses the same no-access
+    // UI with the shared signOut() — that was the GRO-2358 invariant.
+    const noAccess = searchParams.get("noAccess");
+    if (noAccess === "deleted-portal") {
+      setAuthError(
+        "Your portal access has been removed. Please contact your groomer if you think this is a mistake.",
+      );
+    }
 
     if (sessionId) {
       setIsImpersonating(true);
@@ -153,11 +173,13 @@ export function CustomerPortal() {
           setPortalSessionId(data.sessionId);
           setClientName(data.clientName);
         } else if (bridgeResp.status === 404) {
-          // Authenticated but no matching client row — show a friendly message
-          // instead of bouncing back to /login (which would loop indefinitely).
-          setAuthError(
-            "Your account is not linked to a customer record. Please contact your groomer to set up portal access."
-          );
+          // Authenticated but no matching client row — mount the OOBE
+          // (GRO-2359) so the user can create their portal record instead
+          // of landing on the no-access card. The no-access card itself is
+          // still reachable for the deleted-portal case (see GRO-2358) via
+          // the ?noAccess=deleted-portal deep-link, but is no longer in
+          // the new-user path.
+          setShowOOBE(true);
         }
         // 401/other: fall through; App.tsx render guard will redirect to /login.
       } catch {
@@ -280,6 +302,15 @@ export function CustomerPortal() {
   // session state. Dev users are verified via localStorage and the dev-session flow.
   // SSO customers are recognised by portalSessionId (set by the Better Auth bridge).
   if (!session && !portalSessionId) {
+    // GRO-2359 — new-user path: mount the OOBE inline so the SSO bridge's
+    // 404 hands the user a portal-creation form instead of the no-access
+    // card. onCompleted triggers a full page reload to /, which re-runs
+    // the bridge (now with a matching client row) and lands the user in
+    // the portal. A full reload (not React Router navigate) is the
+    // safest reset of the bridge's cached state.
+    if (showOOBE) {
+      return <OOBE onCompleted={() => { window.location.href = "/"; }} />;
+    }
     if (authError) {
       // GRO-1867: graceful 404 fallback — authenticated user has no client row.
       return (