Users can now opt out of embedding GPS coordinates in photos.
The toggle is persisted via SharedPreferences and defaults to enabled.
When disabled, effectiveLocation returns null so no EXIF GPS tags are written.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Documents the app's purpose, architecture, rendering pipeline,
build instructions, and key design decisions (bitmap lifecycle,
thread safety, error handling) established during the recent audit.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
