feat(litespeed): wire up dynamic LSAPI tuning + idle reduction

Two correctness fixes and a tuning improvement.

CORRECTNESS:
1. Strip the stock 'extProcessor lsphp' from httpd_config.conf before
   appending ours. Previously the stock block (hard-coded
   PHP_LSAPI_CHILDREN=10 regardless of container memory) always won
   because our APPEND fragment didn't include an extProcessor block.
   detect-memory-litespeed.sh was computing LSAPI_CHILDREN but never
   plumbing it anywhere — silent dead code.

2. Bump LSPHP_WORKER_ESTIMATE_MB from 96 → 115 per the 2026-06-02
   memory-sizing finding (vantagehealth OOM-spawn loop). Each lsphp
   carries ~115 MB shmem-rss accounted per worker. 115 MB matches the
   real per-worker baseline.

TUNING (idle reduction, the original ask):
- LSAPI_MAX_IDLE_CHILDREN=2  (was CHILDREN/2 = 5 default)
- LSAPI_MAX_IDLE=60s         (was 300s default)
- PHP_LSAPI_MAX_REQUESTS=500 (recycle workers, prevents bloat)
- memSoftLimit=1024M / memHardLimit=1500M per worker (RLIMIT_AS;
  catches runaway scripts at the worker level, cgroup still backstops
  the container)

Effective LSAPI_CHILDREN per container:
  2 GiB → ~17 (was 10 — brain-jar was saturating)
  1 GiB → ~8
  512 MiB → ~3 (cap-marginal per the memory note; bump container if
                site grows)

Dropped LSAPI_MEM_SOFT/HARD computation in detect-memory: AVAILABLE/CHILDREN
was conflating VSZ with RSS-budget arithmetic and would have killed
legitimate workers. The 1024/1500 hard-coded values in the template
comfortably fit typical Divi/WooCommerce VSZ (280-365 MB).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/create-vhost-litespeed.sh

@@ -45,9 +45,12 @@ cp /usr/local/lsws/.conf/httpd_config.conf "$LSWS_CONF/httpd_config.conf"
 
 ## Strip the stock blocks we replace. Use awk: easier than sed range-deletes
 ## to skip a NAMED block of arbitrary length terminated by a top-level `}`.
+## extProcessor lsphp is stripped because the stock one hard-codes
+## PHP_LSAPI_CHILDREN=10 regardless of container size — our appended
+## extProcessor scales it from detect-memory-litespeed.sh.
 awk '
   BEGIN { skip = 0 }
-  /^listener HTTP \{/ || /^listener HTTPS \{/ || /^vhTemplate docker \{/ { skip = 1; next }
+  /^listener HTTP \{/ || /^listener HTTPS \{/ || /^vhTemplate docker \{/ || /^extProcessor lsphp\{/ || /^extProcessor lsphp \{/ { skip = 1; next }
   skip && /^\}/ { skip = 0; next }
   !skip { print }
 ' "$LSWS_CONF/httpd_config.conf" > "$LSWS_CONF/httpd_config.conf.new"
@@ -58,7 +61,7 @@ SENTINEL="## ---- cac-litespeed append (do not edit below) ----"
 {
   echo ""
   echo "$SENTINEL"
-  envsubst '${user} ${domain} ${vhost_map_aliases}' < "$TPL_DIR/httpd_config.tpl"
+  envsubst '${user} ${domain} ${vhost_map_aliases} ${PHPVER} ${LSAPI_CHILDREN}' < "$TPL_DIR/httpd_config.tpl"
 } >> "$LSWS_CONF/httpd_config.conf"
 
 ## --- write our vhost template to /usr/local/lsws/conf/templates/site.conf ---