feat: read camera-embedded rating from RAW/EXIF & XMP

[csiroqa]

Images the user never edited in RapidRAW had no rating (0) because the read path only looked at the .rrdata sidecar and XMP sidecars. Pull a rating from embedded XMP \xmp:Rating\ and the private EXIF Rating tag (0x4746) when .rrdata has none, so camera-assigned stars show up again.

Closes #1130, #517

Description

Star ratings assigned in-camera (e.g. Lumix/Panasonic, Sony) were not shown in RapidRAW because the read path only looked at the .rrdata sidecar (and an optional .xmp file). For images never edited in RapidRAW the .rrdata has rating: 0, and nothing ever pulled the camera's rating back in.

This makes the read path fall back to the two interoperable carriers that cameras/other tools actually use: embedded XMP xmp:Rating and the private EXIF Rating tag (0x4746).

Type of Change

• Bug fix
• New feature
• Breaking change
• Performance improvement
• Code refactoring
• Documentation update
• UI/UX improvement
• Build/CI or Dependency update

Changes Made

• src-tauri/src/exif_processing.rs
  • new read_image_rating(path, bytes): tries embedded XMP xmp:Rating (attribute and element forms) first, then the private EXIF Rating tag (0x4746).
  • xmp:Rating -1 (rejected) is treated as "not a star" (None), so a rejected photo never shows up as a 1-star.
  • unit tests for the XMP/rating mapping.
• src-tauri/src/file_management.rs
  • resolve_image_metadata now, when rating == 0, memory-maps the file and calls read_image_rating to hydrate the rating for display.
  • in-memory only — it does not grow the .rrdata sidecar (avoids FEATURE: The side car file rrdata can be created only for images that is edited/loaded. #1514).

Screenshots/Videos

Testing

• These changes were tested locally by a human and confirmed to work.
• I haven't added any automated tests to the code because the codebase currently lacks a test suite.

Test Configuration:

• OS: (e.g. Windows 11, macOS Sonoma, Ubuntu 24.04)
• Hardware: (e.g. Intel i7, Apple M2, Nvidia RTX 3060)

Checklist

• My code follows the project's code style
• I haven't added unnecessary AI-generated code comments
• My changes generate no new warnings or errors

Additional Notes

Coverage depends on where each camera writes the rating (embedded XMP vs EXIF 0x4746). Reported #1130 (RW2) and #517 (Sony) are the targets; if a specific camera writes elsewhere (e.g. RatingPercent 0x4749), that can be a small follow-up once we have a sample.

AI Disclaimer:

Please state the involvement of AI in this PR:

• This PR is created by an AI agent
• This PR is mostly AI-generated but edited/merged together by a human
• This PR was handwritten with AI assistance (spell check, logic suggestions, error resolving)
• This PR contains only blood, sweat, and coffee (AI-free)

[CyberTimon]

Can you remove the testing suite, remove all code comments and confirm it doesn't do any double reads etc? I haven't had time to test this properly, but I had many file double read scenarios while I tried to also implement this back then

[csiroqa]

Can you remove the testing suite, remove all code comments and confirm it doesn't do any double reads etc? I haven't had time to test this properly, but I had many file double read scenarios while I tried to also implement this back then

I’ve begun to deal with that

[csiroqa]

Updated the branch (2ae8542, c035b79, cef0c7c): testing suite and all comments removed; the rating fallback now reuses the existing read_exif_for_paths read (same mmap), so folder scans add no file reads. Camera rating shows up on demand via the Properties/EXIF read. cargo fmt and clippy (with -D warnings) both pass.

[csiroqa]

the existing EXIF read reused.

• src-tauri/src/exif_processing.rs
  • read_image_rating: embedded XMP xmp:Rating (attribute + element forms) first, then private EXIF Rating (0x4746); -1 ("rejected") → no rating; regexes compiled once.
• src-tauri/src/file_management.rs
  • read_exif_for_paths hydrates Rating into the EXIF map on its existing read (no extra file reads; mmap and fs::read paths both covered).
• src/hooks/useAppNavigation.ts
  • Surfaces the rating into image.rating / imageRatings, so grid stars and rating filter show camera ratings.