ci(forgejo): DOCKER_HOST=host.docker.internal:2375 for DinD jobs

Verified empirically: from a job container the DinD daemon is reachable at
host.docker.internal:2375 (host-gateway 172.17.0.1), not docker-in-docker
(a host-network alias absent inside DinD). Runner container.network reverted
to "" (a host network name is not found inside DinD and fails every job).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.forgejo/workflows/ci.yml

@@ -199,7 +199,7 @@ jobs:
       DATABASE_URL: postgres://trails:trails@localhost:5432/trails
       # The DinD daemon lives at this address on the runner network; the job
       # container needs it explicitly (it has no /var/run/docker.sock).
-      DOCKER_HOST: tcp://docker-in-docker:2375
+      DOCKER_HOST: tcp://host.docker.internal:2375
     steps:
       - uses: actions/checkout@v7
       - uses: pnpm/action-setup@v6
@@ -340,7 +340,7 @@ jobs:
           --health-retries 20
     env:
       DATABASE_URL: postgres://trails:trails@localhost:5432/trails
-      DOCKER_HOST: tcp://docker-in-docker:2375
+      DOCKER_HOST: tcp://host.docker.internal:2375
     steps:
       - uses: actions/checkout@v7
       - uses: pnpm/action-setup@v6