Improve php-fpm -t

Description

if pool.conf contains:

php_admin_value[memory_limit] = 128MB

it does not overwrite the global php.ini,except memory_limit is not set in php.ini, than 128M will be used.

this is either coaccidently the php build in default
OR
an emergc fall back in php-fpm to as in "better try this than nothing"

Suggestion:

add checks to "php-fpm -t" to find:

a) wrong arguments
b) stupid configs which will cause php-fpm master to crash in an endless loop with "code 70"
c) "if you know something, say something"

Example:

if "process.max = 80" is lower than an start servers together ( or other sanity checks ) , than say something and don't lure the using user in a false hope of "it can work" , just to endless crash with "code 70" which tells you: i crash, but not why i crashed" which is VVVVVVEEEEEEERRRYYYY annoying btw.

PHP 8.4.18 (fpm-fcgi) (built: Feb 10 2026 17:48:03) (NTS gcc x86_64)
Copyright (c) The PHP Group
Built by Fedora Project
Zend Engine v4.4.18, Copyright (c) Zend Technologies
with Zend OPcache v8.4.18, Copyright (c), by Zend Technologies

No source files or tests are named. Start by reproducing the reported pool.conf and php.ini behavior with php-fpm -t, then trace the validation entry point and existing failure reporting. Done should include agreed checks for invalid or unsafe configurations, with actionable diagnostics and tests covering them.