Add public read-only mode toggle

TODO.md

@@ -43,20 +43,20 @@ Concrete follow-up work for Jellomator, prioritized by implementation risk and u
 
 ## P2 - UX and Product Improvements
 
-- Replace browser `alert()` with inline form errors/toasts.
-  - Show server errors near submit controls.
-  - Add success toasts for create/update/delete.
-- Remove forced reload in auth forms.
-  - Replace `location.reload()` with state refresh only.
-  - Keep SPA navigation predictable on setup/login/logout.
-- Add drag-and-drop ordering in admin.
-  - Persist `sort_order` updates.
-  - Provide keyboard-accessible move controls as fallback.
-- Add duplicate/cloning for links.
-  - Pre-fill form from an existing link.
-  - Save as new record with unique name validation.
-- Add public read-only mode toggle.
-  - Hide admin entry points and editing affordances for non-admin view.
+- [x] Replace browser `alert()` with inline form errors/toasts.
+  - [x] Show server errors near submit controls.
+  - [x] Add success toasts for create/update/delete.
+- [x] Remove forced reload in auth forms.
+  - [x] Replace `location.reload()` with state refresh only.
+  - [x] Keep SPA navigation predictable on setup/login/logout.
+- [x] Add drag-and-drop ordering in admin.
+  - [x] Persist `sort_order` updates.
+  - [x] Provide keyboard-accessible move controls as fallback.
+- [x] Add duplicate/cloning for links.
+  - [x] Pre-fill form from an existing link.
+  - [x] Save as new record with unique name validation.
+- [x] Add public read-only mode toggle.
+  - [x] Hide admin entry points and editing affordances for non-admin view.
 
 ## P3 - Nice-to-Have
 

frontend/src/app.tsx

@@ -17,6 +17,7 @@ export default function App() {
   const [page, setPage] = useState<Page>('loading');
   const [query, setQuery] = useState('');
   const [toast, setToast] = useState<{ message: string; tone: 'success' | 'error' } | null>(null);
+  const [publicMode, setPublicMode] = useState<boolean>(() => window.localStorage.getItem('public_mode') === '1');
 
   async function refresh() {
     const current = await api.request<SetupState>('/api/me');
@@ -29,7 +30,7 @@ export default function App() {
     if (!current.current_user) {
       setPage(path.startsWith('/admin') ? 'login' : 'dashboard');
     } else {
-      setPage(path.startsWith('/admin') ? 'admin' : 'dashboard');
+      setPage(path.startsWith('/admin') && !publicMode ? 'admin' : 'dashboard');
     }
     setLinks(await api.request<LinkItem[]>('/api/links'));
   }
@@ -43,7 +44,7 @@ export default function App() {
 
   useEffect(() => {
     refresh().catch(() => setPage('setup'));
-  }, []);
+  }, [publicMode]);
 
   useEffect(() => {
     const handlePopState = () => {
@@ -107,6 +108,14 @@ export default function App() {
         query={query}
         setQuery={setQuery}
         canLogout={Boolean(state?.current_user)}
+        canAdmin={Boolean(state?.current_user) && !publicMode}
+        publicMode={publicMode}
+        onTogglePublicMode={() => {
+          const next = !publicMode;
+          setPublicMode(next);
+          window.localStorage.setItem('public_mode', next ? '1' : '0');
+          if (next && window.location.pathname.startsWith('/admin')) nav('/');
+        }}
         onAdmin={() => nav('/admin')}
         onLogout={async () => {
           await api.request('/api/logout', { method: 'POST' });
@@ -155,6 +164,9 @@ function Dashboard({
   query,
   setQuery,
   canLogout,
+  canAdmin,
+  publicMode,
+  onTogglePublicMode,
   onAdmin,
   onLogout,
 }: {
@@ -162,6 +174,9 @@ function Dashboard({
   query: string;
   setQuery: (value: string) => void;
   canLogout: boolean;
+  canAdmin: boolean;
+  publicMode: boolean;
+  onTogglePublicMode: () => void;
   onAdmin: () => void;
   onLogout: () => Promise<void>;
 }) {
@@ -191,8 +206,11 @@ function Dashboard({
       <header className="row-between">
         <h1 className="title-sm">Jellomator</h1>
         <div className="flex items-center gap-2">
+          <button type="button" className="btn-subtle" onClick={onTogglePublicMode}>
+            {publicMode ? 'Exit public mode' : 'Public mode'}
+          </button>
           {canLogout ? <button type="button" className="btn-subtle" onClick={onLogout}>Logout</button> : null}
-          <button type="button" className="btn-subtle" onClick={onAdmin}>Admin</button>
+          {canAdmin ? <button type="button" className="btn-subtle" onClick={onAdmin}>Admin</button> : null}
         </div>
       </header>