feat: sticky header

src/webapp/components/navigation/header/Header.tsx

···
 
 export default function Header(props: Props) {
   return (
-    <Box>
+    <Box pos={'sticky'} top={0} bg={'white'} style={{ zIndex: 1 }}>
       <Group gap={'xs'} p={'xs'} justify="space-between">
         {props.children}
         <Box ml={'auto'}>

src/webapp/features/profile/components/profileHeader/MinimalProfileHeader.tsx

···
 
 export default function MinimalProfileHeader(props: Props) {
   return (
-    <Container px={0} py={'xs'} size={'xl'} mx={0}>
+    <Container p={'xs'} size={'xl'} mx={0}>
       <Group gap={'sm'}>
         <Avatar
           src={props.avatarUrl}

src/webapp/features/profile/components/profileHeader/ProfileHeader.tsx

···
   const profile = await getProfile(props.handle);
 
   return (
-    <Container bg={'white'} p={'xs'} size={'xl'}>
+    <Container bg={'white'} p={0} size={'xl'}>
       <MinimalProfileHeaderContainer
         avatarUrl={profile.avatarUrl}
         name={profile.name}
         handle={profile.handle}
       />
-      <Stack gap={'sm'}>
+      <Stack gap={'sm'} p={'xs'}>
         <Stack gap={'xl'}>
           <Grid gutter={'md'} align={'center'} grow>
             <GridCol span={'auto'}>