✨ feat: migrate to Docker Compose for build cache management

- Replace docker run commands with docker compose
- Use separate docker-compose.build.yml for build cache
- Maintain PostgreSQL service with Docker Compose
- Ensure consistent container networking

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

docker-compose.build.yml

@@ -0,0 +1,16 @@
+services:
+  build-cache:
+    image: gitea.arcodange.lab/arcodange/dance-lessons-coach-build-cache:${DEPS_HASH}
+    build:
+      context: .
+      dockerfile: docker/Dockerfile.build
+      args:
+        DEPS_HASH: ${DEPS_HASH}
+    container_name: dance-lessons-coach-build-cache
+    volumes:
+      - .:/workspace
+    working_dir: /workspace
+    environment:
+      - GOPATH=/go
+      - PATH=/go/bin:/usr/local/go/bin:/usr/local/bin:/usr/bin:/bin
+    restart: unless-stopped