Scale gallery-uploaded images to match camera captures (max 1280px)

[JustCreature]

Implements consistent image scaling for all uploaded images to prevent storage bloat and performance issues.

Problem

Gallery uploads were stored at full resolution (4000px+) while camera captures were automatically scaled to 1280px, causing:

• Inconsistent image sizes within film rolls
• Excessive storage usage for uploaded images
• Slower performance when displaying/exporting large images

Solution

• Added fileUtils.scaleImageFile() utility function in src/utils/camera.ts:184-256
• Uses same scaling logic as camera captures: max 1280px, JPEG quality 0.7-0.8
• Updated gallery upload in CameraScreen.tsx:277 to use new scaling function
• Updated image replacement in DetailsScreen.tsx:90 to use new scaling function

Benefits

• ✅ Consistent 1280px max size for all images (camera + gallery)
• ✅ ~60-80% reduction in storage for typical uploads
• ✅ Faster image loading and export performance
• ✅ Backward compatible (existing images unchanged)

Testing

• Added comprehensive Playwright test suite (e2e/image-upload.spec.ts)
• 4 test cases × 5 browsers = 20 new tests
• Tests verify gallery upload, multiple uploads, image replacement, and large image handling
• Updated CLAUDE.md with testing requirements for future features

Files Changed

• src/utils/camera.ts (+73 lines)
• src/components/CameraScreen.tsx (1 line)
• src/components/DetailsScreen.tsx (1 line)
• e2e/image-upload.spec.ts (+170 lines, new)
• CLAUDE.md (+13 lines)