fix(cac-lsphp): mount docroot at /home/$user + symlink for true 1:1 compatibility

Customer concern: sites with /home/<user>/public_html baked into config or the
DB must keep working — a changed in-container docroot path would break WordPress
ABSPATH, hardcoded includes, cached absolute paths, etc., making the upgrade a
non-drop-in.

Fix: the sidecar now mounts the docroot at /home/$user (IDENTICAL to
cac-fpm/cac-litespeed) and the entrypoint symlinks /mnt/users/<user>/<domain> ->
/home/$user. OLS still serves from its bulk /mnt/users mount and sends lsphp
that path (no remap available), but the symlink resolves it to the real
/home/$user files AND PHP canonicalises it — so __FILE__/__DIR__/realpath/ABSPATH
all report /home/<user>/public_html.

Verified end-to-end through the shared OLS: a request reports
__FILE__=/home/homeuser/public_html/probe.php, ABSPATH=/home/homeuser/public_html/,
and stored /home paths resolve. True 1:1 drop-in.

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

configs/shared-ols/vhconf.tpl

@@ -4,10 +4,10 @@
 ## (matches the shared-vhost-template.tpl convention). One directive per line —
 ## OLS PlainConf does NOT accept ';' separators.
 ##
-## CRITICAL (feedback_ols_lsapi_no_script_filename_remap): docRoot here MUST be
-## the SAME absolute path the cac-lsphp sidecar has mounted, because OLS hands
-## lsphp exactly docRoot+URI as SCRIPT_FILENAME and lsphp opens it. Both are
-## /mnt/users/<user>/<domain>/public_html. The panel asserts this parity.
+## docRoot is /mnt/users/<user>/<domain>/public_html — the shared-ols container's
+## view (bulk /docker/users->/mnt/users mount). OLS sends lsphp exactly this path
+## (no remap); the cac-lsphp sidecar symlinks /mnt/users/<user>/<domain> -> its
+## real /home/<user> mount, so PHP canonicalises it to /home/<user>/public_html.
 
 docRoot                   ~~DOCROOT~~
 enableScript              1