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/entrypoint-litespeed.sh

@@ -47,7 +47,7 @@ chmod 1777 /tmp/lshttpd
 ## ---- memory + lsphp pool sizing ----
 # shellcheck source=/dev/null
 source /scripts/detect-memory-litespeed.sh
-echo "Container memory: ${CONTAINER_MEMORY_MB}MB | LSAPI_CHILDREN=${LSAPI_CHILDREN} | memSoft=${LSAPI_MEM_SOFT}M memHard=${LSAPI_MEM_HARD}M | PHPVER=${PHPVER}"
+echo "Container memory: ${CONTAINER_MEMORY_MB}MB | LSAPI_CHILDREN=${LSAPI_CHILDREN} | PHPVER=${PHPVER}"
 
 ## ---- self-signed cert (idempotent) ----
 mkdir -p /usr/local/lsws/conf/cert