add changes to fix enhancement for layout ui

[Douglasymlai]

• TopBar — refactored middle bar layout; back/forward nav simplified; invite flow moved into a dialog; tooltip shows active task title
• InviteCodeDialog (new) — fetches, caches, and copies invite code from /api/v1/user/invite_code
• ConfigModelCard (new) — animated ring states (configuring / success / error) for model provider config panels
• Models page — wraps provider config UI in ConfigModelCard for save/test feedback
• HistoryTabsNav + Notification — small layout/styling tweaks
• i18n — new invite-code strings across all 12 locales