fix(ci): attach Mongo to the runner container's network

The Forgejo runner is itself a container (visible in 'docker ps' from
inside the job: GITEA-ACTIONS-TASK-N_WORKFLOW-Test_JOB-playwright).
'--network host' for Mongo binds to the outer Docker host's network
namespace, which the runner container can't see — that's why
mongodb://localhost:27017 from the Nuxt server returned ECONNREFUSED.

Drop --network host. Instead, after starting Mongo, look up the
runner container's own network via 'docker inspect $HOSTNAME' and
attach Mongo to it. MONGODB_URI now references the container by
name (mongodb://mongo-ci:27017/...).

.forgejo/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: vitest
     env:
-      MONGODB_URI: mongodb://localhost:27017/ghostguild-test
+      MONGODB_URI: mongodb://mongo-ci:27017/ghostguild-test
       JWT_SECRET: ci-test-jwt-secret
       RESEND_API_KEY: re_ci_dummy_not_used
       HELCIM_API_TOKEN: helcim_ci_dummy_not_used
@@ -41,7 +41,12 @@ jobs:
       - name: Start MongoDB
         run: |
           docker rm -f mongo-ci 2>/dev/null || true
-          docker run -d --name mongo-ci --network host mongo:7
+          docker run -d --name mongo-ci mongo:7
+          # Forgejo runs each job inside its own container; attach Mongo to
+          # that container's network so MONGODB_URI=mongodb://mongo-ci:27017
+          # resolves from inside the runner.
+          RUNNER_NET=$(docker inspect "$HOSTNAME" --format '{{range $k,$v := .NetworkSettings.Networks}}{{$k}} {{end}}' | awk '{print $1}')
+          docker network connect "$RUNNER_NET" mongo-ci
           docker ps
       - name: Wait for MongoDB
         run: timeout 30 sh -c 'until docker exec mongo-ci mongosh --quiet --eval "1" >/dev/null 2>&1; do sleep 1; done'
@@ -85,7 +90,7 @@ jobs:
     needs: vitest
     continue-on-error: true
     env:
-      MONGODB_URI: mongodb://localhost:27017/ghostguild-test
+      MONGODB_URI: mongodb://mongo-ci:27017/ghostguild-test
       JWT_SECRET: ci-test-jwt-secret
       RESEND_API_KEY: re_ci_dummy_not_used
       HELCIM_API_TOKEN: helcim_ci_dummy_not_used
@@ -104,7 +109,12 @@ jobs:
       - name: Start MongoDB
         run: |
           docker rm -f mongo-ci 2>/dev/null || true
-          docker run -d --name mongo-ci --network host mongo:7
+          docker run -d --name mongo-ci mongo:7
+          # Forgejo runs each job inside its own container; attach Mongo to
+          # that container's network so MONGODB_URI=mongodb://mongo-ci:27017
+          # resolves from inside the runner.
+          RUNNER_NET=$(docker inspect "$HOSTNAME" --format '{{range $k,$v := .NetworkSettings.Networks}}{{$k}} {{end}}' | awk '{print $1}')
+          docker network connect "$RUNNER_NET" mongo-ci
           docker ps
       - name: Wait for MongoDB
         run: timeout 30 sh -c 'until docker exec mongo-ci mongosh --quiet --eval "1" >/dev/null 2>&1; do sleep 1; done'