deploy: build on every service so build <svc> can't no-op

build: . lived only on mavend, so `docker compose build mavweb` (or any other
module) silently built nothing and redeployed a stale mavenai:latest — a fixed
binary looked deployed but wasn't. Moved build into the shared anchor; same
image name means it's still built once, but naming any service now rebuilds.

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

docker-compose.yml

@@ -9,13 +9,16 @@ x-image: &image
   # NOT "maven" — that's Apache Maven on Docker Hub and compose will happily
   # pull it, giving every container `mvn-entrypoint.sh` and exit 127.
   image: mavenai:latest
+  # build on EVERY service (same image name ⇒ built once) so `docker compose
+  # build <anyservice>` actually rebuilds. With build on only one service, the
+  # others silently no-op and you deploy a stale binary.
+  build: .
   pull_policy: never   # only ever the locally-built image
   restart: unless-stopped
 
 services:
   mavend:
     <<: *image
-    build: .
     command: ["mavend", "-config", "/opt/maven/config/mavend.json"]
     # the key lives ONLY here. deploy/db_key.env holds MAVEN_DB_KEY=<base64-32B>.
     env_file: [./deploy/db_key.env]