feat: enhance layout and sidebar functionality with new PageHeader and SidebarContext

src/pages/ActivityPage.tsx

@@ -3,11 +3,6 @@ import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/com
 export function ActivityPage() {
   return (
     <div className="space-y-6">
-      <div>
-        <h1 className="text-3xl font-bold">Activity</h1>
-        <p className="text-muted-foreground">View recent activity and logs</p>
-      </div>
-
       <div className="grid gap-6 md:grid-cols-2 lg:grid-cols-3">
         <Card>
           <CardHeader>

src/pages/AdminUsersPage.tsx

@@ -51,14 +51,6 @@ export function AdminUsersPage() {
 
   return (
     <div className="space-y-6">
-      <div className="flex items-center justify-between">
-        <div>
-          <h1 className="text-3xl font-bold">User Management</h1>
-          <p className="text-muted-foreground">Manage users and their permissions</p>
-        </div>
-        <Button>Add User</Button>
-      </div>
-
       <Card>
         <CardHeader>
           <CardTitle>Users</CardTitle>

src/pages/DashboardPage.tsx

@@ -10,11 +10,6 @@ export function DashboardPage() {
 
   return (
     <div className="space-y-6">
-      <div>
-        <h1 className="text-3xl font-bold">Dashboard</h1>
-        <p className="text-muted-foreground">Welcome back, {user.name}!</p>
-      </div>
-
       <div className="grid gap-6 md:grid-cols-2 lg:grid-cols-3">
         {/* User Profile Card */}
         <Card>

src/pages/LoginPage.tsx

@@ -42,7 +42,9 @@ export function LoginPage() {
     const loadProviders = async () => {
       try {
         const providers = await authService.getOAuthProviders()
-        setOauthProviders(providers)
+        if (providers) {
+          setOauthProviders(providers)
+        }
       } catch (error) {
         console.error('Failed to load OAuth providers:', error)
       }

src/pages/RegisterPage.tsx

@@ -33,7 +33,9 @@ export function RegisterPage() {
     const loadProviders = async () => {
       try {
         const providers = await authService.getOAuthProviders()
-        setOauthProviders(providers)
+        if (providers) {
+          setOauthProviders(providers)
+        }
       } catch (error) {
         console.error('Failed to load OAuth providers:', error)
       }

src/pages/SettingsPage.tsx

@@ -39,11 +39,6 @@ export function SettingsPage() {
 
   return (
     <div className="space-y-6">
-      <div>
-        <h1 className="text-3xl font-bold">Settings</h1>
-        <p className="text-muted-foreground">Manage your account settings and preferences</p>
-      </div>
-
       <div className="grid gap-6 md:grid-cols-2">
         <Card>
           <CardHeader>