Correct the PHP-FPM process-model wording in the docs

docs/advanced/portable-config.md

@@ -145,7 +145,7 @@ $portable = PortableConfig::loadSigned($store->load(), $secret);
 $firewall = new Firewall((new Config($cache))->combine($portable));
 ```
 
-Under classic PHP-FPM each request is a fresh process, so this runs once per request and always reflects the current rules. To avoid querying the database on every request, put a shared cache (APCu, for example) in front of the store.
+Under classic PHP-FPM userland state does not carry over between requests, so this runs once per request and always reflects the current rules. To avoid querying the database on every request, put a shared cache (APCu, for example) in front of the store.
 
 ### Long-running workers
 

docs/faq.md

@@ -274,7 +274,7 @@ Yes, Phirewall accepts any PSR-16 (PHP Standard Recommendation for Simple Cachin
 
 ### Why does InMemoryCache not work in production?
 
-In PHP-FPM (FastCGI Process Manager), each request starts a new process (or reuses one from the pool). The in-memory cache is empty at the start of each request, so counters always reset to zero. This means rate limits and ban counters never accumulate.
+In PHP-FPM (FastCGI Process Manager), worker processes are pooled and reused across requests, but PHP tears down userland state at the end of each request. The in-memory cache therefore starts empty on every request, so counters always reset to zero. This means rate limits and ban counters never accumulate.
 
 Under long-running worker runtimes (Swoole, RoadRunner, FrankenPHP worker mode, Octane) the failure is the opposite and easy to miss: the array survives across requests within a worker, so a single-worker demo looks like it "works", but each worker is a separate process with its own array. State is never shared across workers (counters and bans fragment, so the effective rate limit is roughly N times the configured value) and the array grows for the worker's lifetime.
 

docs/features/storage.md

@@ -33,7 +33,7 @@ $config = new Config($cache);
 ### Characteristics
 
 - Zero external dependencies
-- Data resets on every request in PHP-FPM (each request is a new process)
+- Data resets on every request in PHP-FPM (userland state does not persist between requests)
 - Under long-running worker runtimes (Swoole, RoadRunner, FrankenPHP worker mode, Octane) the array lives for the worker's lifetime: state is **not** shared across workers (each worker is a separate process, so counters and bans fragment) and the array only evicts already-expired entries, so it is not a memory cap. This makes it unsafe as a firewall store there; see the warning below.
 - Implements both `CacheInterface` (PSR-16) and `CounterStoreInterface`
 - Automatic expired entry purging every 1000 operations