fix: start nginx before boot logs so HF captures output

HF's log API only streams logs after the container port is open.
Start nginx first (background), then print boot info so HF
captures it. Added heartbeat every 60s for monitoring.

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

ubuntu-server/start-server.sh

@@ -10,6 +10,17 @@ exec 2>&1
 export SSH_PORT="${SSH_PORT:-2222}"
 export TTYD_PORT="${TTYD_PORT:-7681}"
 
+# ── Start nginx FIRST so HF sees port 7860 and starts capturing logs ──
+nginx -g 'daemon off;' &
+NGINX_PID=$!
+
+# Forward signals to nginx for clean shutdown
+trap "kill $NGINX_PID 2>/dev/null; wait $NGINX_PID 2>/dev/null; exit" SIGTERM SIGINT SIGQUIT
+
+# Small delay to let nginx bind and HF detect the port
+sleep 2
+
+# ── Now print boot info (HF is streaming logs at this point) ──────
 echo "========================================"
 echo "[ubuntu] HuggingRun Ubuntu Server"
 echo "[ubuntu] $(date -u)"
@@ -69,10 +80,10 @@ fi
 # ── Process summary ──────────────────────────────────────────────
 echo "========================================"
 echo "[ubuntu] Services:"
+echo "[ubuntu]   nginx         PID=${NGINX_PID}   0.0.0.0:7860"
 echo "[ubuntu]   sshd          PID=${SSHD_PID}   127.0.0.1:${SSH_PORT}"
 echo "[ubuntu]   ws-ssh-bridge PID=${BRIDGE_PID}  127.0.0.1:7862"
 echo "[ubuntu]   ttyd          PID=${TTYD_PID}    127.0.0.1:${TTYD_PORT}"
-echo "[ubuntu]   nginx         (foreground)       0.0.0.0:7860"
 echo "========================================"
 
 # ── Installed packages ───────────────────────────────────────────
@@ -83,7 +94,13 @@ echo "[ubuntu] Current packages: $(dpkg-query -W -f='\n' 2>/dev/null | wc -l)"
 echo "[ubuntu] All processes:"
 ps aux --no-headers 2>/dev/null | awk '{printf "[ubuntu]   %-8s PID=%-6s %s\n", $1, $2, $11}' || true
 
-# ── nginx (foreground, port 7860) ────────────────────────────────
-echo "[ubuntu] Starting nginx on 0.0.0.0:7860 (foreground) ..."
 echo "[ubuntu] ══ System ready ══"
-exec nginx -g 'daemon off;'
+
+# ── Heartbeat: periodic log so we can always see the system is alive ──
+(while true; do
+    sleep 60
+    echo "[ubuntu] heartbeat: $(date -u) | load=$(cat /proc/loadavg 2>/dev/null | cut -d' ' -f1-3) | mem=$(free -h 2>/dev/null | awk '/Mem:/{print $3"/"$2}' || echo '?')"
+done) &
+
+# ── Wait for nginx (keep shell as PID 1 for signal handling) ─────
+wait $NGINX_PID