refactor(docker): make image-based the default compose, build variant is .dev

Less confusion: docker-compose.yml is now the default (pulls pre-built images)
and the build-on-host variant is docker-compose.dev.yml. Updated all references
(CLAUDE.md, README, .env.example, build-push-images.mjs, compose header).

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

scripts/build-push-images.mjs

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 // Build the three NovaSonic images and push them to your registry, so the production host just PULLS
-// (docker-compose.prod.yml) instead of building. Run from your dev machine after changes:
+// (docker-compose.yml) instead of building. Run from your dev machine after changes:
 //
 //   npm run push-images                 # builds + pushes REGISTRY/*:TAG (and :latest)
 //
@@ -53,4 +53,4 @@ for (const [name, ctx] of Object.entries(images)) {
 }
 
 console.log(`\n✔ Alle Images gebaut + gepusht (${REGISTRY}/*:${TAG}). Auf dem Server:`);
-console.log('   docker compose -f docker-compose.prod.yml pull && docker compose -f docker-compose.prod.yml up -d');
+console.log('   docker compose pull && docker compose up -d');