fix(cac-lsphp): normalize $_SERVER DOCUMENT_ROOT/SCRIPT_FILENAME to /home

The symlink makes __FILE__/__DIR__/realpath/getcwd report /home/<user>/public_html
(WordPress/frameworks), but $_SERVER['DOCUMENT_ROOT']/['SCRIPT_FILENAME'] are raw
env vars OLS sets to its /mnt/users view — apps that build/compare paths from
them would see /mnt/users. Added a tiny auto_prepend (cac-lsphp-normalize.php,
wired via a scan-dir ini) that realpath-canonicalises those two back to /home.
Customer sites have no auto_prepend by default, so no conflict.

Verified clean-room (committed image, fresh boot): DOCUMENT_ROOT and
SCRIPT_FILENAME both report /home/<user>/public_html through the shared OLS.
Now byte-for-byte 1:1 with cac-fpm/cac-litespeed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Dockerfile.lsphp

@@ -41,6 +41,7 @@ RUN apt-get update && \
 COPY ./scripts/entrypoint-lsphp.sh \
      ./scripts/detect-memory-lsphp.sh \
      ./scripts/healthcheck-lsphp.sh \
+     ./scripts/cac-lsphp-normalize.php \
      /scripts/
 RUN chmod +x /scripts/entrypoint-lsphp.sh /scripts/detect-memory-lsphp.sh /scripts/healthcheck-lsphp.sh