Add Image Compression & Optimization

Implement image compression and optimization for generated memes to reduce file sizes and improve download speeds without compromising quality.

## Current State
Generated memes are saved at full resolution, resulting in large file sizes that may be slow to download.

## Tasks
- [ ] Add image compression library (e.g., `sharp` in Node.js or `Pillow` in Python)
- [ ] Implement multiple quality levels (high/medium/low)
- [ ] Add compression settings in the API endpoint
- [ ] Generate WebP format as alternative for better compression
- [ ] Display file size info before download
- [ ] Add compression settings UI in download dialog

## Expected Output
- Meme images are 40-60% smaller without noticeable quality loss
- Users can choose compression quality
- Download times are significantly reduced

## Files to Modify
- `meme-bot/meme_generator_clean.py` (add compression logic)
- `api/caption.js` (add compression for Imgflip-generated memes)
- `src/components/Dynamicmeme.jsx` (add UI controls)
- `src/Meme.jsx` (add UI controls)

## Technical Details
- Use `Pillow` with `optimize=True` and quality parameter for Python
- Consider JPEG quality: 70-80 for good balance
- Add WebP format option for modern browsers