fix(db): set shm_size 1g — parallel queries overflow default 64MB /dev/shm

Postgres parallel workers (e.g. sitemap_index) need >64MB shared memory;
Docker's default /dev/shm cap raised DiskFull ("No space left on device").

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.yml

@@ -1,6 +1,7 @@
 services:
   db:
     image: postgres:16-alpine
+    shm_size: 1g  # parallel workers (np. seo.sitemap_index) potrzebują >64MB /dev/shm
     environment:
       POSTGRES_USER: ${POSTGRES_USER:-goon}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-goon}