IAV-1266/bugfix(sav): improve integration tabs, ticketing exclusivity, and Freshdesk modal flow
- IntegrationTabs: support disabled tabs, sync active tab when defaultTab changes, ignore clicks on disabled tabs.
- ToggleButton: explicit disabled styling and pass-through to MUI Button.
- IntegrationCard: when IAVIA ticketing is active, block Freshdesk toggle with tooltip; keep Freshdesk switch off until user can switch/connect properly.
- IntegrationConnectionModal: add optional initialView (Freshdesk defaults to configure).
- IaviaConfigView: allow async onTicketingSystemChange and await after activation.