fix: use native Imagick for AVIF and HEIC output instead of magick convert

[loks0n]

Summary

• AVIF and HEIC output previously shelled out to magick convert, which is unreliable in containerised environments where the binary may not be on PATH
• ImageMagick 7 with the heic/avif delegates exposes AVIF and HEIC encoding directly through the Imagick PHP extension — no shell exec needed
• Switch the avif/heic case to the same native pattern used by jpg, png, and gif: setImageCompressionQuality + setImageFormat, then let the shared getImagesBlob/writeImages path handle output

Test plan

• Convert a JPEG/PNG to AVIF via the preview endpoint and verify image/avif content-type and non-empty body
• Convert a JPEG/PNG to HEIC via the preview endpoint and verify image/heic content-type and non-empty body
• Verify quality parameter is respected (compare file sizes at different quality settings)
• Confirm no temp files are left behind

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR replaces the shell-exec-based magick convert path for AVIF and HEIC output with native Imagick PHP extension calls (setImageFormat + setCompressionQuality), bringing these formats in line with the jpg/png/gif pattern. The implementation correctly uses the object-level setCompressionQuality() instead of setImageCompressionQuality() for AVIF/HEIC, with a well-documented comment explaining the libheif coder quirk (Imagick issue #711).

Confidence Score: 5/5

Safe to merge — clean refactor with no new bugs introduced and a real reliability problem fixed.

All findings are P2 or lower. The core logic correctly mirrors the existing jpg/png/gif pattern, the quality quirk is well-documented and technically justified, and the prior resource-cleanup concern (blob path) pre-exists across all formats and was already noted. No blocking issues remain.

No files require special attention.

Important Files Changed

Filename	Overview
src/Image/Image.php	Removes 55 lines of shell-exec logic for AVIF/HEIC; replaces with 4-line native Imagick path consistent with other formats. Quality handling correctly uses object-level setCompressionQuality() per documented Imagick/libheif behaviour.
tests/Image/ImageTest.php	Updates expected HEIC file size from 8426 to 8490 bytes to match native-encoder output; all other test assertions are unchanged.

_{Reviews (3): Last reviewed commit: "fix: use setCompressionQuality for AVIF/..." | Re-trigger Greptile}