RunCloud

RunCloud support is partial:

build works. It compiles libde265, libheif and ImageMagick 7 into /opt/heic-ios18-fix using the normal Debian/Ubuntu toolchain.
PHP and FPM wiring is not implemented. The script detects /RunCloud, refuses to guess at RunCloud's paths, and prints a TODO(runcloud) message.

Unverified paths

The following paths are expected but have not been confirmed on a real RunCloud server. They are marked TODO(runcloud) in heic-fix.sh:

Purpose	Expected path
PHP binary	`/RunCloud/Packages/phpXXrc/bin/php`
CLI config	`/etc/phpXXrc/cli/conf.d`
FPM config	`/etc/phpXXrc/fpm/conf.d`
Module config	`/etc/phpXXrc/mods-available`
FPM binary	`/RunCloud/Packages/phpXXrc/sbin/php-fpm` or `phpXXrc-fpm`
FPM service	`phpXXrc-fpm`
Pool configs	`/etc/phpXXrc/fpm/pool.d`

sudo /opt/heic-ios18-fix/heic-fix.sh build -y

This gives you:

/opt/heic-ios18-fix/heif/bin/heif-dec — the isolated decoder, usable from a WordPress upload hook,
/opt/heic-ios18-fix/imagemagick/bin/magick — ImageMagick 7, with libheif linked statically into MagickCore,
private libheif-heicfix.so.1 / libde265-heicfix.so.0 for the diagnostic tools.

You can convert an upload with heif-dec without touching PHP's Imagick:

/opt/heic-ios18-fix/heif/bin/heif-dec --quiet photo.heic photo.jpg

Implement these hooks in heic-fix.sh and remove the corresponding TODO(runcloud) markers:

php_versions — enumerate installed phpXXrc stacks.
php_bin — return the RunCloud CLI binary.
phpize_bin / php_config_bin — point at the matching build tools.
fpm_bin — return the RunCloud FPM binary.
enable_ext / disable_ext — write the equivalent of mods-available/imagick-heic.ini and toggle the stock module.
reload_fpm — reload the RunCloud FPM unit.
site_map — map RunCloud sites to PHP versions.

Send a pull request with the verified paths and a verify transcript.

The script detects RunCloud by the presence of /RunCloud.
build still uses apt-get with needrestart disabled.
Do not run the script's check, php, enable, rollback or verify commands on RunCloud until the hooks are implemented; they exit with an explicit not-implemented error instead of making a wrong change.