fix: UI polish and provider fixes

- Add animate-pulse CSS animation for loading states
- Add Ctrl+I/Ctrl+B markdown shortcuts in chat input
- Improve chat input resize with mirror element
- Add reasoning duration display and shimmer effect
- Add confirmation dialog for deleting all models
- Simplify RowVirtualizerDynamic resize handling
- Fix DialogType imports (type -> value)
- Fix ollama cloud model name resolution
- Make vllm auth header optional
- Various icon and styling fixes

app/components/Sidenav/Header.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import type { DialogType } from '~/composables/useDialog';
+import { DialogType } from '~/composables/useDialog';
 
 const { user, signOut } = useAuth();