chore(project): name the app container tfm

Give the app service an explicit container_name so it shows up as `tfm`
instead of the generated `tanabata-app-1`.

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

docker-compose.yml

@@ -23,6 +23,7 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+    container_name: tfm
     restart: unless-stopped
 
     # All application config (secrets, DATABASE_URL, tunables) comes from .env.