refactor(wizard): move onboarding wizard state into WizardProvider

Lift the onboarding wizard's open state, first-login auto-open effect, and the
wizard render itself out of App into WizardProvider. Feed, Channels, and
SettingsPanel trigger it via useWizard() instead of an onOpenWizard prop; App
and ChannelPage drop the prop plumbing. First step of S6b.3 — removing the
per-module props that block a uniform registry render. (Platform S6b.3)

frontend/src/App.tsx

@@ -53,7 +53,6 @@ import ErrorDialog from "./components/ErrorDialog";
 import VersionBanner from "./components/VersionBanner";
 import DemoBanner from "./components/DemoBanner";
 import { focusAccessRequestsTab } from "./lib/adminUsersTab";
-import { shouldAutoOpenOnboarding } from "./lib/onboarding";
 import { CURRENT_VERSION } from "./lib/releaseNotes";
 
 // Route-level code splitting: each module page (and the heavier modals) is its own lazy chunk,
@@ -74,7 +73,6 @@ const SettingsPanel = lazy(() => import("./components/SettingsPanel"));
 const NotificationsPanel = lazy(() => import("./components/NotificationsPanel"));
 const Messages = lazy(() => import("./components/Messages"));
 const DownloadCenter = lazy(() => import("./components/DownloadCenter"));
-const OnboardingWizard = lazy(() => import("./components/OnboardingWizard"));
 const About = lazy(() => import("./components/About"));
 const ReleaseNotes = lazy(() => import("./components/ReleaseNotes"));
 
@@ -127,7 +125,6 @@ export default function App() {
     plex: loadLayout("plex"),
     playlists: loadLayout("playlists"),
   }));
-  const [wizardOpen, setWizardOpen] = useState(false);
   const [aboutOpen, setAboutOpen] = useState(false);
   const [notesOpen, setNotesOpen] = useState(false);
   const [notesHighlight, setNotesHighlight] = useState<string | undefined>(undefined);
@@ -337,13 +334,6 @@ export default function App() {
     stripUrlParams();
   }, [adminDeepLink, meQuery.data?.id]); // eslint-disable-line react-hooks/exhaustive-deps
 
-  // First-login onboarding: prompt the user to connect YouTube (and resume the flow after
-  // each consent redirect). Derived from granted scopes + storage flags so it's stable
-  // across the full-page OAuth round-trip; dismissible and reopenable from Settings.
-  useEffect(() => {
-    if (meQuery.data && shouldAutoOpenOnboarding(meQuery.data)) setWizardOpen(true);
-  }, [meQuery.data?.id, meQuery.data?.can_read, meQuery.data?.can_write]);
-
   // On login, adopt server-stored preferences.
   useEffect(() => {
     const prefs = meQuery.data?.preferences;
@@ -576,7 +566,7 @@ export default function App() {
           >
           <Suspense fallback={pageFallback}>
           {page === "channels" ? (
-            <Channels me={meQuery.data!} onOpenWizard={() => setWizardOpen(true)} />
+            <Channels me={meQuery.data!} />
           ) : page === "stats" ? (
             <Stats me={meQuery.data!} />
           ) : page === "scheduler" && meQuery.data!.role === "admin" ? (
@@ -598,11 +588,7 @@ export default function App() {
           ) : page === "downloads" && !meQuery.data!.is_demo ? (
             <DownloadCenter me={meQuery.data!} />
           ) : page === "settings" ? (
-            <SettingsPanel
-              me={meQuery.data!}
-              prefs={prefsCtl}
-              onOpenWizard={() => setWizardOpen(true)}
-            />
+            <SettingsPanel me={meQuery.data!} prefs={prefsCtl} />
           ) : page === "plex" && meQuery.data!.plex_enabled ? (
             <PlexBrowse />
           ) : (
@@ -613,7 +599,6 @@ export default function App() {
               setView={setView}
               canRead={meQuery.data!.can_read}
               isDemo={meQuery.data!.is_demo}
-              onOpenWizard={() => setWizardOpen(true)}
               ytSearch={ytSearch}
               onYtSearch={enterYtSearch}
               onExitYtSearch={exitYtSearch}
@@ -629,9 +614,6 @@ export default function App() {
       </div>
       {meQuery.data && !meQuery.data.is_demo && <ChatDock meId={meQuery.data.id} />}
       <Suspense fallback={null}>
-        {wizardOpen && meQuery.data && !meQuery.data.is_demo && (
-          <OnboardingWizard me={meQuery.data} onClose={() => setWizardOpen(false)} />
-        )}
         {aboutOpen && (
           <About
             onClose={() => setAboutOpen(false)}