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>

scripts/entrypoint-lsphp.sh

@@ -90,6 +90,15 @@ if [ -n "$SCAN_DIR" ]; then
 ; rendered at container start by entrypoint-lsphp.sh
 error_log = /home/${user}/logs/php-fpm/error.log
 log_errors = On
+EOF
+  ## Normalise \$_SERVER['DOCUMENT_ROOT']/['SCRIPT_FILENAME'] from the OLS-sent
+  ## /mnt/users path back to /home/<user> so cac-lsphp is byte-for-byte 1:1 with
+  ## cac-fpm. Customer sites have no auto_prepend by default, so this is safe; a
+  ## site that sets its own .user.ini auto_prepend overrides it (paths still
+  ## resolve via the symlink either way).
+  cat > "$SCAN_DIR/99-cac-lsphp-normalize.ini" <<'EOF'
+; rendered at container start by entrypoint-lsphp.sh
+auto_prepend_file = /scripts/cac-lsphp-normalize.php
 EOF
   ## Per-site opcache override (panel: Advanced Tuning → OpCache size); falls
   ## back to the baked lsphp-overrides.ini defaults when unset.