feat: implement photo upload component with EXIF extraction

- Add PhotoUpload component with drag-and-drop interface
- Integrate exifr library for GPS and timestamp extraction
- Implement file validation (type, size)
- Add photo previews with metadata overlay
- Support multiple photo uploads (max 5 files, 5MB each)
- Display GPS indicators and extracted metadata
- Create demo page for testing component
- Satisfies requirements 1.2, 1.3, 1.4, 1.5, 8.3

.kiro/specs/beach-litter-mapping/tasks.md

@@ -32,7 +32,7 @@
   - Implement filter state management and map updates
   - _Requirements: 2.4, 2.5_
 
-- [-] 5. Create heat map visualization
+- [x] 5. Create heat map visualization
   - Integrate Leaflet.heat plugin
   - Implement heat map toggle control
   - Configure heat map intensity based on report density
@@ -41,7 +41,7 @@
 
 ## Report Submission System
 
-- [ ] 6. Build photo upload component with EXIF extraction
+- [x] 6. Build photo upload component with EXIF extraction
   - Create drag-and-drop photo upload interface
   - Implement file type and size validation
   - Integrate exifr library to extract GPS coordinates and timestamps