Fix naming conflict

synapse/docker-compose.yml

@@ -1,5 +1,5 @@
 services:
-  db:
+  synapse_db:
     image: docker.io/library/postgres:17
     restart: unless-stopped
     volumes:
@@ -17,7 +17,7 @@ services:
       SYNAPSE_SERVER_NAME: ${SYNAPSE_SERVER_NAME}
       SYNAPSE_REPORT_STATS: "no"
       SYNAPSE_ENABLE_REGISTRATION: "true"
-      SYNAPSE_POSTGRES_HOST: db
+      SYNAPSE_POSTGRES_HOST: synapse_db
       SYNAPSE_POSTGRES_USER: ${POSTGRES_USER}
       SYNAPSE_POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
       SYNAPSE_POSTGRES_DB: ${POSTGRES_DB}
@@ -25,5 +25,5 @@ services:
       - "8008:8008"
       - "8448:8448"
     depends_on:
-      - db
+      - synapse_db