feat: make page title consistent

frontend/src/pages/(navbar)/exercise-panel.tsx

frontend/src/pages/(navbar)/graphiql.tsx

frontend/src/pages/(navbar)/index.tsx

frontend/src/pages/(navbar)/settings.tsx

frontend/src/pages/404.tsx

frontend/src/pages/analyst/_layout.tsx

...uctor/[exerciseId]/[teamId]/[channelId]/email/_layout.tsx

frontend/src/pages/instructor/_layout.tsx

frontend/src/pages/instructor/index.tsx

frontend/src/pages/login.tsx

...ainee/[exerciseId]/[teamId]/[channelId]/email/_layout.tsx

frontend/src/pages/trainee/_layout.tsx

frontend/src/pages/users/_layout.tsx

frontend/src/pages/users/index.tsx