ci: docker compose (prod + isolated e2e) and Gitea CI pipeline

Prod compose: Traefik labels for space-wanderer.dev.kkhost.pl, ./db volume mount.
CI compose: project space-wanderer-ci on external network space-wanderer-ci-e2e with
the app pinned to static IP 172.39.0.10 (Flight-Ops mechanism verbatim, distinct
network name so both stacks coexist on the shared dind daemon), fresh named DB volume
per run. ci.yml: single 'build + unit + e2e' job — required status check name kept;
flaky-uplink retry loops, dep/browser caches, dind cleanup + prune carried over.

docker-compose.yml

@@ -0,0 +1,17 @@
+services:
+  space-wanderer:
+    build: .
+    volumes:
+      # Game state SQLite: created on first run, must survive rebuilds.
+      - "./db:/app/db"
+    networks:
+      - dev_net
+    labels:
+      - "traefik.enable=true"
+      - "traefik.http.routers.space-wanderer.rule=Host(`space-wanderer.dev.kkhost.pl`)"
+      - "traefik.http.routers.space-wanderer.entrypoints=web"
+      - "traefik.http.services.space-wanderer.loadbalancer.server.port=3000"
+
+networks:
+  dev_net:
+    external: true