Update Dockerfile and environment configuration for Gitea runner and Flutter CI integration

docker-compose.yml

@@ -7,13 +7,22 @@ services:
     container_name: gitea-runner
     restart: unless-stopped
     environment:
-      GITEA_INSTANCE_URL: ${GITEA_INSTANCE_URL}
-      GITEA_RUNNER_REGISTRATION_TOKEN: ${GITEA_RUNNER_REGISTRATION_TOKEN}
+      GITEA_INSTANCE_URL: ${GITEA_INSTANCE_URL:?Set GITEA_INSTANCE_URL in .env}
+      GITEA_RUNNER_REGISTRATION_TOKEN: ${GITEA_RUNNER_REGISTRATION_TOKEN:?Set GITEA_RUNNER_REGISTRATION_TOKEN in .env}
       GITEA_RUNNER_NAME: ${GITEA_RUNNER_NAME:-recipe-app}
-      GITEA_RUNNER_LABELS: ${GITEA_RUNNER_LABELS:-backend-node24:docker://node:24-bullseye,flutter-3-41:docker://ghcr.io/cirruslabs/flutter:stable}
+      GITEA_RUNNER_LABELS: ${GITEA_RUNNER_LABELS:-backend-node24:docker://node:24.15.0-bullseye,flutter-3-41:docker://recipe-flutter-ci:3.41-node24}
     volumes:
       - runner-data:/data
       - /var/run/docker.sock:/var/run/docker.sock
+    security_opt:
+      - no-new-privileges:true
+    tmpfs:
+      - /tmp
+    logging:
+      driver: json-file
+      options:
+        max-size: "10m"
+        max-file: "3"
     healthcheck:
       test: ["CMD-SHELL", "pgrep -x act_runner > /dev/null || exit 1"]
       interval: 30s