feat(backend): add daemon control scripts start, stop, status

backend/start.sh

@@ -0,0 +1,22 @@
+#!/data/data/com.termux/files/usr/bin/bash
+cd "$(dirname "$0")"
+
+# Acquire Android partial wake-lock so CPU does not sleep when screen turns off
+/data/data/com.termux/files/usr/bin/termux-wake-lock 2>/dev/null || true
+
+# Stop existing backend instance if running
+if [ -f katproxy.pid ]; then
+  kill $(cat katproxy.pid) 2>/dev/null || true
+  rm -f katproxy.pid
+fi
+sleep 0.5
+
+# Rotate log file to save tablet storage
+if [ -f katproxy.log ]; then
+  tail -n 200 katproxy.log > katproxy.log.tmp 2>/dev/null && mv katproxy.log.tmp katproxy.log 2>/dev/null || true
+fi
+
+# Start backend with 256MB capped V8 heap for ARM Android stability
+PORT=5050 nohup node --max-old-space-size=256 server.js >> katproxy.log 2>&1 &
+echo $! > katproxy.pid
+echo "katproxy-backend running with PID $(cat katproxy.pid) on port 5050"

backend/status.sh

@@ -0,0 +1,23 @@
+#!/data/data/com.termux/files/usr/bin/bash
+cd "$(dirname "$0")"
+
+echo "=== KatProxy Backend Status ==="
+if [ -f katproxy.pid ]; then
+  PID=$(cat katproxy.pid)
+  if ps -p "$PID" > /dev/null 2>&1; then
+    echo "Status: RUNNING (PID $PID)"
+    ps -o pid,user,%cpu,%mem,vsz,rss,stat,start,time,comm -p "$PID" 2>/dev/null || ps -p "$PID"
+  else
+    echo "Status: STALE PID FILE (Process $PID not active)"
+  fi
+else
+  echo "Status: STOPPED (no katproxy.pid)"
+fi
+
+echo ""
+echo "=== Last Log Lines ==="
+if [ -f katproxy.log ]; then
+  tail -n 15 katproxy.log
+else
+  echo "No katproxy.log found."
+fi

backend/stop.sh

@@ -0,0 +1,11 @@
+#!/data/data/com.termux/files/usr/bin/bash
+cd "$(dirname "$0")"
+
+if [ -f katproxy.pid ]; then
+  PID=$(cat katproxy.pid)
+  kill "$PID" 2>/dev/null && echo "Stopped katproxy-backend (PID $PID)" || echo "Process $PID not running"
+  rm -f katproxy.pid
+else
+  pkill -f "katproxy-backend" 2>/dev/null || true
+  echo "No katproxy.pid file found."
+fi