docker to be more inline with other projects and best practices

docker/php.ini

@@ -0,0 +1,41 @@
+; PreAuth php.ini overrides — merged on top of the FrankenPHP base image
+; defaults.
+;
+; The base image ships no php.ini (only the php.ini-production template), so
+; the production switches that matter are stated explicitly here rather than
+; inherited — verified against a real boot: without them the response carries
+; `X-Powered-By: PHP/8.5.10` and errors would render into the body.
+;
+; PreAuth keeps its session state in APCu plus a filesystem cache pool, so the
+; settings that matter most are the cache ones.
+
+; Never advertise the interpreter, never print errors to the client. This is
+; an authentication gateway: a stack trace in a 500 body is an information
+; leak. Errors go to stderr for the log collector.
+expose_php = Off
+display_errors = Off
+log_errors = On
+error_log = /proc/self/fd/2
+
+memory_limit = 256M
+upload_max_filesize = 2M
+post_max_size = 8M
+
+; OPcache for the FrankenPHP worker: the image is immutable, so timestamps
+; never need revalidating. The CLI console also runs the app, hence
+; enable_cli = 1.
+opcache.enable = 1
+opcache.enable_cli = 1
+opcache.validate_timestamps = 0
+opcache.memory_consumption = 128
+opcache.interned_strings_buffer = 16
+opcache.max_accelerated_files = 20000
+
+; APCu — nonce cache, rate limiter and session cache all live in it, and the
+; console needs it too (`bin/console` commands manage cache state).
+apc.enabled = 1
+apc.enable_cli = 1
+apc.shm_size = 64M
+apc.ttl = 0
+
+date.timezone = UTC