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

package.json

@@ -13,6 +13,7 @@
     "@clerk/clerk-react": "^5.55.0",
     "@tanstack/react-query": "^5.90.9",
     "date-fns": "^4.1.0",
+    "exifr": "^7.1.3",
     "leaflet": "^1.9.4",
     "leaflet.heat": "^0.2.0",
     "leaflet.markercluster": "^1.5.3",