feat(service): implement PID-file based service management (DAW/furt#100)

- Replace unreliable pexp patterns with PID-file approach
- Add graceful shutdown with timeout handling in rc.d script
- Implement process validation after startup
- Add SIGHUP config reload support for Unix services
- Ensure PID-file cleanup on service exit
- Update systemd service to use PIDFile parameter

Platform improvements:
- OpenBSD: rc_check/rc_stop functions now PID-file based
- Linux: systemd Type=forking with proper PIDFile support
- Cross-platform: /var/run/furt.pid standard location

Resolves service status detection issues where rcctl check showed
(failed) despite running service due to process name variations
across platforms.

deployment/linux/furt.service

@@ -6,7 +6,8 @@ After=network.target
 Type=forking
 User=furt
 Group=furt
-ExecStart=/usr/local/share/furt/scripts/start.sh start
+ExecStart=/usr/local/share/furt/scripts/start.sh
+PIDFile=/var/run/furt.pid
 WorkingDirectory=/usr/local/share/furt
 Restart=always
 RestartSec=5

deployment/openbsd/rc.d-furt

@@ -3,11 +3,52 @@
 daemon="/usr/local/share/furt/scripts/start.sh"
 daemon_user="_furt"
 daemon_cwd="/usr/local/share/furt"
-daemon_flags="start"
 
 . /etc/rc.d/rc.subr
 
-pexp="lua.*src/main.lua"
+# PID-File location
+pidfile="/var/run/furt.pid"
+
+# Custom rc_check function (PID-File based)
+rc_check() {
+    [ -f "$pidfile" ] && kill -0 $(cat "$pidfile") 2>/dev/null
+}
+
+# Custom rc_stop function (PID-File based)
+rc_stop() {
+    if [ -f "$pidfile" ]; then
+        local _pid=$(cat "$pidfile")
+        echo "Stopping furt (PID: $_pid)"
+        kill "$_pid" 2>/dev/null
+        # Wait for process to die
+        local _timeout=10
+        while [ $_timeout -gt 0 ] && kill -0 "$_pid" 2>/dev/null; do
+            sleep 1
+            _timeout=$((_timeout - 1))
+        done
+        # Force kill if still running
+        if kill -0 "$_pid" 2>/dev/null; then
+            echo "Force killing furt (PID: $_pid)"
+            kill -9 "$_pid" 2>/dev/null
+        fi
+        rm -f "$pidfile"
+        echo "furt stopped"
+    else
+        echo "furt not running (no PID-File)"
+    fi
+}
+
+# Custom rc_reload function (signal-based)
+rc_reload() {
+    if rc_check; then
+        local _pid=$(cat "$pidfile")
+        echo "Reloading furt configuration (PID: $_pid)"
+        kill -HUP "$_pid"
+    else
+        echo "furt not running"
+        return 1
+    fi
+}
 
 rc_cmd $1
 

scripts/start.sh

@@ -19,8 +19,10 @@ LUA_COMMAND=""
 # Config check first
 if [ "$(uname)" = "OpenBSD" ] || [ "$(uname)" = "FreeBSD" ]; then
     CONFIG_FILE="/usr/local/etc/furt/furt.conf"
+    PID_FILE="/var/run/furt.pid"
 else
     CONFIG_FILE="/etc/furt/furt.conf"
+    PID_FILE="/var/run/furt.pid"
 fi
 
 if [ ! -f "$CONFIG_FILE" ] && [ ! -f "$PROJECT_DIR/config/furt.conf" ]; then
@@ -87,12 +89,38 @@ cd "$PROJECT_DIR"
 
 echo -e "${GREEN}Starting Furt...${NC}"
 
+# PID-File cleanup function
+cleanup_pid() {
+    if [ -f "$PID_FILE" ]; then
+        rm -f "$PID_FILE"
+    fi
+}
+
 # Service vs Interactive Detection
 if [ ! -t 0 ] || [ ! -t 1 ]; then
-    # Service mode - Background
+    # Service mode - Background + PID-File
+    echo -e "${GREEN}Service mode: Background + PID-File${NC}"
+
+    # Start process in background
     "$LUA_COMMAND" src/main.lua &
+    PID=$!
+
+    # Write PID-File
+    echo "$PID" > "$PID_FILE"
+    echo -e "${GREEN}Furt started (PID: $PID, PID-File: $PID_FILE)${NC}"
+
+    # Verify process is still running after short delay
+    sleep 1
+    if ! kill -0 "$PID" 2>/dev/null; then
+        echo -e "${RED}Error: Process died immediately${NC}"
+        cleanup_pid
+        exit 1
+    fi
+
+    echo -e "${GREEN}Service startup successful${NC}"
 else
-    # Interactive mode - Foreground
+    # Interactive mode - Foreground (no PID-File)
+    echo -e "${GREEN}Interactive mode: Foreground${NC}"
     exec "$LUA_COMMAND" src/main.lua
 fi