Pin container names in QA compose to match Caddy's upstream hostnames

Caddy reverse-proxies to novelly-web/novelly-api by DNS name, but compose
only registered aliases web/api (service names) plus novelly-web-1/-api-1
(container-number suffixed). Any Caddy restart re-resolves DNS and 502s
until the alias exists again. Pin container_name so the alias is stable
across every redeploy.

deploy/qa/docker-compose.qa.yml

@@ -8,6 +8,7 @@ services:
 
   api:
     image: ${API_IMAGE}:latest
+    container_name: novelly-api
     restart: unless-stopped
     environment:
       ConnectionStrings__Novel: "Data Source=/data/novel.db"
@@ -29,6 +30,7 @@ services:
 
   web:
     image: ${WEB_IMAGE}:latest
+    container_name: novelly-web
     restart: unless-stopped
     depends_on:
       api: