adding opencode to the environment

.opencode-sandbox/docker-compose.yml

@@ -0,0 +1,23 @@
+services:
+  opencode:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: opencode-sandbox
+    container_name: opencode
+    cap_add:
+      - NET_ADMIN   # required for iptables in entrypoint
+      - NET_RAW
+    volumes:
+      # Your monorepo — opencode's working directory
+      - ../:/workspace
+      # Persist opencode auth so you don't re-login every time
+      - opencode-auth:/root/.local/share/opencode
+    environment:
+      - OPENCODE_API_KEY=${OPENCODE_API_KEY}
+    stdin_open: true
+    tty: true
+    working_dir: /workspace
+
+volumes:
+  opencode-auth: