feat: Enhanced Slides Generator with animated presentations and file attachments

Major improvements:
- MODERN ANIMATED SLIDES: CSS3 animations (fadeIn, slideIn, scaleIn, pulse)
  SVG charts and data visualizations, glassmorphism effects, gradient backgrounds
  Professional typography, staggered reveal animations

- FILE ATTACHMENT SUPPORT: Upload PowerPoint, PDFs, Docs, Images, Color Palettes
  Auto-extract colors from images for brand consistency
  Parse CSS/JSON files for color palettes
  Context-aware slide generation from attached documents

- ENHANCED THEMING: 8 premium themes (Corporate Blue, Executive Dark, Tech Neon, etc.)
  4 animation styles (Professional, Dynamic, Minimal, Impressive)
  7 audience presets with style descriptions

- IMPROVED UX: Drag-and-drop file upload zone
  Progress bar during presentation playback
  Enhanced HTML export with autoplay and keyboard navigation
  File size display and color palette preview

lib/services/model-adapter.ts

@@ -194,6 +194,10 @@ export class ModelAdapter {
       slideCount?: number;
       audience?: string;
       organization?: string;
+      animationStyle?: string;
+      audienceStyle?: string;
+      themeColors?: string[];
+      brandColors?: string[];
     } = {},
     provider?: ModelProvider,
     model?: string