Implement Password Grant Flow for Authentication and Enhance User Experience

- Introduced Password Grant Flow for user authentication, allowing direct login with email and password.
- Updated `useAuth` composable to manage login and logout processes, including Single Sign-Out from Cidaas.
- Enhanced user interface with a new `UserMenu` component displaying user information and logout functionality.
- Updated homepage to show personalized greetings for logged-in users and a login prompt for guests.
- Added logout confirmation page with a countdown redirect to the homepage.
- Documented the implementation details and future enhancements for OAuth2 flows in CLAUDE.md and other relevant documentation.
- Added test credentials and guidelines for automated testing in the new TESTING.md file.

app/components/ui/dropdown-menu/index.ts

@@ -0,0 +1,16 @@
+export { default as DropdownMenu } from "./DropdownMenu.vue"
+
+export { default as DropdownMenuCheckboxItem } from "./DropdownMenuCheckboxItem.vue"
+export { default as DropdownMenuContent } from "./DropdownMenuContent.vue"
+export { default as DropdownMenuGroup } from "./DropdownMenuGroup.vue"
+export { default as DropdownMenuItem } from "./DropdownMenuItem.vue"
+export { default as DropdownMenuLabel } from "./DropdownMenuLabel.vue"
+export { default as DropdownMenuRadioGroup } from "./DropdownMenuRadioGroup.vue"
+export { default as DropdownMenuRadioItem } from "./DropdownMenuRadioItem.vue"
+export { default as DropdownMenuSeparator } from "./DropdownMenuSeparator.vue"
+export { default as DropdownMenuShortcut } from "./DropdownMenuShortcut.vue"
+export { default as DropdownMenuSub } from "./DropdownMenuSub.vue"
+export { default as DropdownMenuSubContent } from "./DropdownMenuSubContent.vue"
+export { default as DropdownMenuSubTrigger } from "./DropdownMenuSubTrigger.vue"
+export { default as DropdownMenuTrigger } from "./DropdownMenuTrigger.vue"
+export { DropdownMenuPortal } from "reka-ui"