fix: restore frontend page headings

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/components/layout/WorkspaceUtilities.tsx

@@ -1,4 +1,4 @@
-import {CalendarDays, Inbox, Mail} from 'lucide-react'
+import { CalendarDays, Mail } from 'lucide-react'
 import { NavLink } from 'react-router-dom'
 import type { User } from '../../types'
 
@@ -8,7 +8,7 @@ export function WorkspaceUtilities({user}: { user: User | null }) {
     <nav className="workspace-utilities" aria-label="Account navigation">
       <NavLink className="utility-link" to="/inbox">
         <Mail size={18} aria-hidden="true" />
-                <span>Invitations</span>
+        <span>Inbox</span>
       </NavLink>
       <NavLink className="utility-link" to="/calendar">
         <CalendarDays size={18} aria-hidden="true" />

frontend/src/components/ui/PageHeader.tsx

@@ -15,6 +15,7 @@ export function PageHeader({
     <header className="page-header">
       <div>
         <span className="eyebrow">{eyebrow}</span>
+        <h1>{title}</h1>
         {description && <p>{description}</p>}
       </div>
       {action}