From ab45bc063ddb0ab585897cdaaac8560b94226573 Mon Sep 17 00:00:00 2001
From: Nexus Dev <nexus@local>
Date: Fri, 10 Apr 2026 17:11:17 +0000
Subject: [PATCH] fix(nexus): auto-recover from unknown company prefix

When the URL contains a :companyPrefix segment that doesn't match any
fetched company, Layout previously rendered a dead-end NotFoundPage
with no recovery link. The sidebar's company switcher depends on
selectedCompany being non-null, so users landing on a bogus prefix
had no way back without hand-typing a new URL.

Replace the NotFoundPage branch with a redirect to the same path under
the first available company (selectedCompany ?? companies[0]). If the
rest of the path is empty, fall back to /dashboard so the target is
guaranteed to exist. The hasUnknownCompanyPrefix condition is already
gated on companies.length > 0, so the fallback is reachable; the old
NotFoundPage remains as a theoretical safety net if somehow both
selectedCompany and companies[0] are null.

Triggered by a user session after the embedded-postgres wipe: the
browser had a stale localStorage selectedCompanyId and the user
hand-typed URLs with guessed prefixes like /ASSISTANT/company/settings.
Hitting any invalid prefix stranded them on the 404 with no UI to
pick a different company.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 ui/src/components/Layout.tsx | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/ui/src/components/Layout.tsx b/ui/src/components/Layout.tsx
index 28773668..c918dcb5 100644
--- a/ui/src/components/Layout.tsx
+++ b/ui/src/components/Layout.tsx
@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useQuery } from "@tanstack/react-query";
 import { BookOpen, MessageSquare, Moon, Settings, Sun } from "lucide-react";
-import { Link, Outlet, useLocation, useNavigate, useParams } from "@/lib/router";
+import { Link, Navigate, Outlet, useLocation, useNavigate, useParams } from "@/lib/router";
 import { CompanyRail } from "./CompanyRail";
 import { Sidebar } from "./Sidebar";
 import { InstanceSidebar } from "./InstanceSidebar";
@@ -460,10 +460,31 @@ export function Layout() {
               )}
             >
               {hasUnknownCompanyPrefix ? (
-                <NotFoundPage
-                  scope="invalid_company_prefix"
-                  requestedPrefix={companyPrefix ?? selectedCompany?.issuePrefix}
-                />
+                // [nexus] Auto-recover from bogus URL prefixes by redirecting
+                // to the same path under the first available company, instead
+                // of leaving the user stranded on an "Invite not available"
+                // style dead end with no way back. hasUnknownCompanyPrefix is
+                // already gated on companies.length > 0, so the fallback is
+                // guaranteed to resolve. If no fallback exists for some reason,
+                // fall through to the old NotFoundPage.
+                (() => {
+                  const fallbackCompany = selectedCompany ?? companies[0] ?? null;
+                  if (!fallbackCompany) {
+                    return (
+                      <NotFoundPage
+                        scope="invalid_company_prefix"
+                        requestedPrefix={companyPrefix ?? undefined}
+                      />
+                    );
+                  }
+                  const restOfPath = location.pathname.replace(/^\/[^/]+/, "") || "/dashboard";
+                  return (
+                    <Navigate
+                      to={`/${fallbackCompany.issuePrefix}${restOfPath}${location.search}${location.hash}`}
+                      replace
+                    />
+                  );
+                })()
               ) : (
                 <Outlet />
               )}