fix(ci): increase idle timeout to 60min, check act_runner children

The 15min timeout was too short for Rust builds. Also checks
for act_runner child processes (image pull, git clone phases)
not just Docker containers.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infra/modules/ci-runner/cloud-init.yaml.tpl

@@ -63,12 +63,23 @@ write_files:
       IDLE_FILE="/tmp/ci-idle-since"
       TIMEOUT_SEC=$((${idle_timeout_minutes} * 60))
 
-      RUNNING=$(docker ps -q --filter "name=GITEA-ACTIONS" 2>/dev/null | wc -l)
-      if [ "$RUNNING" -gt 0 ]; then
+      # Check for running Docker containers
+      CONTAINERS=$(docker ps -q 2>/dev/null | wc -l)
+      if [ "$CONTAINERS" -gt 0 ]; then
         rm -f "$IDLE_FILE"
         exit 0
       fi
 
+      # Check if act_runner has child processes (actively running a job)
+      RUNNER_PID=$(pgrep -f 'act_runner daemon' 2>/dev/null)
+      if [ -n "$RUNNER_PID" ]; then
+        CHILDREN=$(pgrep -P "$RUNNER_PID" 2>/dev/null | wc -l)
+        if [ "$CHILDREN" -gt 0 ]; then
+          rm -f "$IDLE_FILE"
+          exit 0
+        fi
+      fi
+
       # No jobs running — record when idle started
       if [ ! -f "$IDLE_FILE" ]; then
         date +%s > "$IDLE_FILE"

infra/modules/ci-runner/variables.tf

@@ -65,7 +65,7 @@ variable "runner_capacity" {
 variable "idle_timeout_minutes" {
   description = "Minutes idle before auto-shutdown (0 = disabled)"
   type        = number
-  default     = 15
+  default     = 60
 }
 
 variable "gitea_tailscale_host" {