fix: add runner-entrypoint.sh to register Forgejo runner on first start

The data.forgejo.org/forgejo/runner image doesn't auto-register from
env vars — it needs create-runner-file called explicitly before the
daemon starts. The entrypoint handles registration on first run (no
/data/.runner file) then execs the daemon on all subsequent starts.

https://claude.ai/code/session_01FKCW3FDjNFj6jve4niMFXH

infra/docker-compose.yml

@@ -109,14 +109,16 @@ services:
     image: data.forgejo.org/forgejo/runner:6
     container_name: act_runner
     restart: unless-stopped
+    command: ["/entrypoint.sh"]
     environment:
       FORGEJO_INSTANCE_URL: https://${FORGEJO_DOMAIN}
-      FORGEJO_RUNNER_REGISTRATION_TOKEN: ${FORGEJO_RUNNER_TOKEN}
+      FORGEJO_RUNNER_TOKEN: ${FORGEJO_RUNNER_TOKEN}
       FORGEJO_RUNNER_NAME: hiy-runner
       # Give the runner access to Podman so CI jobs can build/run containers.
       DOCKER_HOST: tcp://podman-proxy:2375
     volumes:
       - act_runner_data:/data
+      - ./runner-entrypoint.sh:/entrypoint.sh:ro
     depends_on:
       - forgejo
       - podman-proxy

infra/runner-entrypoint.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+# runner-entrypoint.sh — register the Forgejo runner on first start, then run the daemon.
+#
+# On first run (no /data/.runner file) it calls create-runner-file to register
+# with the Forgejo instance using FORGEJO_RUNNER_TOKEN. On subsequent starts it
+# goes straight to the daemon.
+set -e
+
+CONFIG=/data/.runner
+
+if [ ! -f "$CONFIG" ]; then
+    echo "[runner] No registration found — registering with Forgejo…"
+    forgejo-runner create-runner-file \
+        --instance  "${FORGEJO_INSTANCE_URL}" \
+        --secret    "${FORGEJO_RUNNER_TOKEN}" \
+        --name      "${FORGEJO_RUNNER_NAME:-hiy-runner}" \
+        --connect
+    echo "[runner] Registration complete."
+fi
+
+echo "[runner] Starting daemon…"
+exec forgejo-runner daemon --config "$CONFIG"