feat(web): make settings tabs URL-addressable via ?tab=

Add an optional `tab` search param (validated against the known tab set)
to /dashboard/settings and drive the Tabs component from it, so each tab
is shareable/bookmarkable (e.g. /dashboard/settings?tab=referral). Tab
clicks update the URL with replace to avoid history spam; existing links
need no search param since `tab` is optional.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/components/settings/settings-content.tsx

@@ -35,7 +35,13 @@ import {
 import { useEffect, useState } from "react";
 import { ChangelogTab } from "./changelog-tab";
 
-export function SettingsContent() {
+export function SettingsContent({
+  tab,
+  onTabChange,
+}: {
+  tab: string;
+  onTabChange: (next: string) => void;
+}) {
   const { t } = useTranslation();
   const { user, signOut } = useAuth();
 
@@ -161,7 +167,7 @@ export function SettingsContent() {
     <div className="mx-auto max-w-3xl space-y-6">
       <h2 className="text-2xl font-bold">{t("settings.title")}</h2>
 
-      <Tabs defaultValue="profile">
+      <Tabs value={tab} onValueChange={onTabChange}>
         <TabsList className="w-full flex-wrap">
           <TabsTrigger value="profile" className="gap-2">
             <User className="h-4 w-4" />

apps/web/src/routes/dashboard/settings.tsx

@@ -8,11 +8,31 @@ const SettingsContent = lazy(() =>
   })),
 );
 
+export const SETTINGS_TABS = [
+  "profile",
+  "security",
+  "connections",
+  "referral",
+  "account",
+  "changelog",
+] as const;
+export type SettingsTab = (typeof SETTINGS_TABS)[number];
+
+function isSettingsTab(value: unknown): value is SettingsTab {
+  return SETTINGS_TABS.includes(value as SettingsTab);
+}
+
 export const Route = createFileRoute("/dashboard/settings")({
+  // `tab` is optional so existing <Link to="/dashboard/settings"> need no search param.
+  validateSearch: (search: Record<string, unknown>): { tab?: SettingsTab } =>
+    isSettingsTab(search.tab) ? { tab: search.tab } : {},
   component: SettingsPage,
 });
 
 function SettingsPage() {
+  const { tab } = Route.useSearch();
+  const navigate = Route.useNavigate();
+
   return (
     <Suspense
       fallback={
@@ -23,7 +43,10 @@ function SettingsPage() {
         </div>
       }
     >
-      <SettingsContent />
+      <SettingsContent
+        tab={tab ?? "profile"}
+        onTabChange={(next) => navigate({ search: { tab: next as SettingsTab }, replace: true })}
+      />
     </Suspense>
   );
 }