fix: revert to FastCGI TCP — Unix socket requires root on FPM master

Unix socket volume was root-owned, FPM running as uid 1000 couldn't
create the socket. TCP app:9000 works without privilege changes and
has negligible performance difference in a local Docker network.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -8,7 +8,6 @@ services:
       HOME: /tmp
     volumes:
       - .:/var/www
-      - php_socket:/var/run/php
     depends_on:
       postgres:
         condition: service_healthy
@@ -25,7 +24,6 @@ services:
       - ./docker/caddy/Caddyfile:/etc/caddy/Caddyfile
       - .:/var/www
       - caddy_data:/data
-      - php_socket:/var/run/php
     depends_on:
       - app
 
@@ -122,7 +120,6 @@ volumes:
   postgres_data:
   redis_data:
   caddy_data:
-  php_socket:
 
 networks:
   default:

docker/app/Dockerfile

@@ -17,4 +17,3 @@ COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
 WORKDIR /var/www
 
 COPY docker/app/php.ini /usr/local/etc/php/conf.d/app.ini
-COPY docker/app/www.conf /usr/local/etc/php/php-fpm.d/www.conf

docker/caddy/Caddyfile

@@ -4,7 +4,7 @@
 
 ss3k.schaunwama.de {
     root * /var/www/public
-    php_fastcgi unix//var/run/php/php-fpm.sock
+    php_fastcgi app:9000
     file_server
     encode gzip