docs: update README with Sprint 1 features (drag/drop, presets, shortcuts)

README.md

@@ -1,6 +1,6 @@
 # PNGer - Modern PNG Editor & Resizer
 
-A sleek, modern PNG editor and resizer with **live preview**, **dark/light mode theming**, and direct upload/download features. Built with TypeScript and deployed as a single Docker container on Unraid.
+A sleek, modern PNG editor and resizer with **live preview**, **drag & drop**, **smart presets**, **keyboard shortcuts**, and **dark/light mode theming**. Built with TypeScript and deployed as a single Docker container on Unraid.
 
 ## ✨ Features
 
@@ -26,12 +26,31 @@ A sleek, modern PNG editor and resizer with **live preview**, **dark/light mode
 - **Fit Modes**: Inside (resize only) or Cover (crop to fill)
 
 ### 🚀 Performance & Usability
+- **Drag & Drop**: Drag images directly into the app or use file browser
+- **Clipboard Paste**: Paste images with Ctrl+V (Cmd+V on Mac)
+- **Smart Presets**: Quick access to common configurations:
+  - 📷 Web Optimized (1920x1080, 80% quality, WebP)
+  - 📱 Social Media (1080x1080, 85% quality, JPEG)
+  - 👤 Profile Picture (400x400, 90% quality, PNG)
+  - 📧 Email Friendly (800x600, 75% quality, JPEG)
+  - ⭐ Tiny Icon (64x64, 100% quality, PNG)
+  - 🔍 Retina 2x (2x dimensions, 90% quality)
+  - 💎 Icon Small (256x256, 95% quality, PNG)
+  - 🔶 Icon Large (512x512, 95% quality, PNG)
+- **Keyboard Shortcuts**: Fast workflow with keyboard controls (see below)
 - **Direct Download**: No server-side storage, immediate download
 - **Modern UI**: Sleek, responsive TypeScript/Svelte design
 - **File Analysis**: Original size, transformed size, savings percentage
 - **Debounced Updates**: Smooth preview generation (300ms delay)
 - **Visual Feedback**: Loading states, error messages, success indicators
 
+### ⌨️ Keyboard Shortcuts
+- **Ctrl+V** (Cmd+V): Paste image from clipboard
+- **Enter**: Transform & Download (works when input not focused)
+- **Ctrl+Enter** (Cmd+Enter): Transform & Download (works anywhere)
+- **?**: Show/hide keyboard shortcuts help
+- **Esc**: Close shortcuts dialog
+
 ## Tech Stack
 
 - **Frontend**: Svelte 4 + Vite + TypeScript
@@ -162,7 +181,7 @@ docker run -d \
 
 ```
 pnger/
-├── frontend/                # Svelte + TypeScript application
+├── frontend/              # Svelte + TypeScript application
 │   ├── src/
 │   │   ├── App.svelte      # Main UI component (with live preview)
 │   │   ├── main.ts         # Entry point
@@ -170,11 +189,12 @@ pnger/
 │   │   └── lib/
 │   │       ├── api.ts      # API client
 │   │       ├── preview.ts  # Live preview logic
-│   │       └── theme.ts    # Theme management store
+│   │       ├── theme.ts    # Theme management store
+│   │       └── presets.ts  # Smart presets configuration
 │   ├── package.json
 │   ├── tsconfig.json
 │   └── vite.config.ts
-├── backend/                 # Express + TypeScript API server
+├── backend/               # Express + TypeScript API server
 │   ├── src/
 │   │   ├── index.ts        # Express server
 │   │   ├── routes/
@@ -183,20 +203,21 @@ pnger/
 │   │       └── image.ts    # TypeScript types
 │   ├── package.json
 │   └── tsconfig.json
-├── Dockerfile               # Multi-stage build (frontend + backend)
+├── Dockerfile              # Multi-stage build (frontend + backend)
-├── docker-compose.yml       # Unraid deployment config
+├── docker-compose.yml      # Unraid deployment config
 ├── ROADMAP.md              # Feature roadmap
-└── UI_UPGRADE_NOTES.md     # UI upgrade documentation
+├── SPRINT1_CHANGES.md      # Sprint 1 implementation details
+└── UI_UPGRADE_NOTES.md    # UI upgrade documentation
 ```
 
 ## How It Works
 
-1. User uploads an image via the web interface
+1. User uploads an image via drag & drop, file browser, or clipboard paste
 2. **Live preview** generates instantly using Canvas API
-3. User adjusts parameters (width, height, quality, format, etc.)
+3. User adjusts parameters (width, height, quality, format, etc.) or selects a preset
 4. Preview updates in real-time (debounced 300ms)
 5. User sees file size comparison and savings
-6. When satisfied, user clicks "Transform & Download"
+6. When satisfied, user clicks "Transform & Download" or presses Enter
 7. Frontend sends image + parameters to backend API
 8. Backend processes using Sharp (resize, crop, compress, convert)
 9. Processed image returned directly to browser
@@ -250,20 +271,48 @@ All configuration is handled via environment variables passed through Docker/Unr
 - **Instant Updates**: Debounced at 300ms for smooth performance
 - **Canvas-Based**: No server load, runs in browser
 
+### Drag & Drop Upload
+- **Drop Zone**: Large, responsive drop target with visual feedback
+- **Multiple Methods**: Drag & drop, click to browse, or paste from clipboard
+- **File Validation**: Instant validation with clear error messages
+- **Visual States**: Hover and dragging states for better UX
+
+### Smart Presets
+- **8 Pre-configured Options**: Common use cases ready to go
+- **One-Click Apply**: Instantly sets all parameters
+- **Visual Icons**: Easy identification of each preset
+- **Responsive Grid**: Adapts to screen size
+
+### Keyboard Shortcuts
+- **Productivity Focused**: Common operations accessible via keyboard
+- **Help Dialog**: Press ? to see all shortcuts
+- **Context Aware**: Enter works differently based on focus
+- **Cross-Platform**: Supports both Ctrl and Cmd modifiers
+
 ### Image Analysis
 - Original file size displayed
 - Preview size estimation
 - Savings/increase percentage
 - Visual feedback with color coding
 
+## Recent Updates (Sprint 1)
+
+✅ **Drag & Drop Upload** - Drag images directly into the app
+✅ **Clipboard Paste** - Paste images with Ctrl+V
+✅ **Smart Presets** - 8 quick-access presets for common scenarios
+✅ **Keyboard Shortcuts** - Fast workflow with keyboard controls
+✅ **Enhanced UX** - Better visual feedback and error handling
+✅ **Theme Contrast Fixes** - Improved text visibility in both themes
+
+See [SPRINT1_CHANGES.md](./SPRINT1_CHANGES.md) for detailed implementation notes.
+
 ## Roadmap
 
 See [ROADMAP.md](./ROADMAP.md) for planned features including:
-- Drag & drop upload
 - Batch processing
-- Smart presets
+- Advanced crop tool with visual selector
 - Watermarking
-- Advanced crop tool
+- Image filters and effects
 - And more!
 
 ## License
@@ -284,3 +333,9 @@ Sleek black interface with light gold accents, ideal for viewing light/transpare
 
 ### Live Preview
 Side-by-side comparison showing original and transformed image with file size analysis
+
+### Smart Presets
+Quick-access buttons for common image optimization scenarios
+
+### Keyboard Shortcuts
+Built-in help dialog showing all available shortcuts