HEIC / HEIF decoder notices

The active worker uses libheif 1.23.7 with libde265 1.1.3, built from unmodified pinned
upstream source archives using Emscripten 3.1.61. The decoder is loaded in a
separate worker only when a HEIC/HEIF picture is processed. Pictures and decoded
pixels remain in the browser; they are not uploaded.

libheif and libde265 are covered by GNU LGPL v3.
Copyright notices and full GNU GPL / LGPL texts accompany this distribution:
  /vendor/heif/LICENSE-libheif.txt
  /vendor/heif/LICENSE-libde265.txt

The library is separately loaded; interface-compatible modified libraries may
replace libheif-1.23.7.js and libheif-1.23.7.wasm. The application places no runtime integrity
lock on such modification or relinking. The application's integration source is
served as /heif-core.js, /heif-decoder.js, /heif-worker.js and is in the repository:
https://github.com/ssap-k/saenghwal-toolkit

Active files and exact corresponding source:
  /vendor/heif/libheif-1.23.7.js
  /vendor/heif/libheif-1.23.7.wasm
  /vendor/heif/libheif-1.23.7-source.tar.gz
  /vendor/heif/libde265-source.tar.gz
  /vendor/heif/build-local-1.23.7.txt       actual Windows build recipe
  /vendor/heif/build-instructions-1.23.7.txt
  /vendor/heif/build-workflow-1.23.7.txt    Ubuntu reference recipe
  /vendor/heif/manifest.json               binary/source SHA256 and build identity
  /vendor/heif/versions.json               actual active build versions

Only the libde265 HEVC decoder is enabled. Encoders, dynamic plugins,
parallel decoding, OpenJPEG, uncompressed HEIF and other codecs remain disabled.
WASM memory is capped at 512MiB. Both source archives are unmodified.

Compatibility for already cached workers:
The unversioned libheif.js/libheif.wasm pair remains the unchanged 1.23.6 build.
It is not selected by the current worker. Its exact source is still supplied
as libheif-source.tar.gz, and build-workflow.txt records that earlier recipe.
The legacy pair is retained together so an already loaded old worker cannot
combine one old file with a new one during a deployment. A page reload uses
the current worker and versioned active pair. Active/legacy paths and versions
are explicit in manifest.json. Both remain separately replaceable.

Upstream:
https://github.com/strukturag/libheif
https://github.com/strukturag/libde265
https://github.com/emscripten-core/emsdk

No HEIC encoding, patent license, identity-photo approval or original HDR/metadata
preservation is represented by this decoder notice.