Implement: Custom Spinner/Loading Component

[dokterbob]

Objective

Create a custom spinner component to replace Flowbite Spinner.

Component Locations

• SubmitButton.svelte - Loading state during submission
• ChatWaiting.svelte - Loading indicator

Options

1. Use Lucide icon with animation (e.g., Loader2)
2. Create custom SVG spinner
3. Use CSS-only spinner
4. Find ShadCDN-compatible spinner package

Tasks

• Research spinner implementation options
• Create Spinner component in ui folder
• Add size variants (sm, md, lg)
• Implement animation with Tailwind
• Replace Flowbite Spinner usage
• Test performance

Implementation Example

<!-- Option 1: Lucide Icon -->
<script>
  import { Loader2 } from 'lucide-svelte';
</script>
<Loader2 class="animate-spin h-4 w-4" />

<!-- Option 2: Custom Component -->
<Spinner size="sm" class="text-primary" />

Acceptance Criteria

• Smooth animation
• Customizable size and color
• Low performance impact
• Works in all browsers