♻️(frontend) prioritize full name display before email

Why? user friendly, and more human-readable identifier. Should
be enhance later on, to display both info together.

src/frontend/src/features/settings/components/SettingsDialog.tsx

@@ -18,7 +18,7 @@ export const SettingsDialog = (props: SettingsDialogProps) => {
           <P>
             <Trans
               i18nKey="settings:account.currentlyLoggedAs"
-              values={{ user: user?.email }}
+              values={{ user: user?.full_name || user?.email }}
               components={[<Badge />]}
             />
           </P>

src/frontend/src/features/settings/components/tabs/AccountTab.tsx

@@ -48,7 +48,7 @@ export const AccountTab = ({ id, onOpenChange }: AccountTabProps) => {
           <P>
             <Trans
               i18nKey="settings:account.currentlyLoggedAs"
-              values={{ user: user?.email }}
+              values={{ user: user?.full_name || user?.email }}
               components={[<Badge />]}
             />
           </P>

src/frontend/src/layout/Header.tsx

@@ -76,7 +76,7 @@ export const Header = () => {
                   tooltip={t('loggedInUserTooltip')}
                   tooltipType="delayed"
                 >
-                  {user.email}
+                  {user?.full_name || user?.email}
                 </Button>
                 <MenuList
                   items={[{ value: 'logout', label: t('logout') }]}