feat: add dev-daemon target for background development mode

Add a new make dev-daemon target that allows running DeerFlow services
in background mode without keeping the terminal connection.

Following the pattern of PR #1042, the implementation uses a dedicated
shell script (scripts/start-daemon.sh) for better maintainability.

- Create scripts/start-daemon.sh for daemon mode startup
- Add dev-daemon target to Makefile
- Each service writes logs to separate files (langgraph, gateway, frontend, nginx)
- Services can be stopped with make stop
- Use nohup for proper daemon process detachment
- Add cleanup on failure when services fail to start
- Use more specific pkill pattern to avoid killing unrelated nginx processes

scripts/start-daemon.sh

@@ -0,0 +1,131 @@
+#!/usr/bin/env bash
+#
+# start-daemon.sh - Start all DeerFlow development services in daemon mode
+#
+# This script starts DeerFlow services in the background without keeping
+# the terminal connection. Logs are written to separate files.
+#
+# Must be run from the repo root directory.
+
+set -e
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+# ── Stop existing services ────────────────────────────────────────────────────
+
+echo "Stopping existing services if any..."
+pkill -f "langgraph dev" 2>/dev/null || true
+pkill -f "uvicorn src.gateway.app:app" 2>/dev/null || true
+pkill -f "next dev" 2>/dev/null || true
+nginx -c "$REPO_ROOT/docker/nginx/nginx.local.conf" -p "$REPO_ROOT" -s quit 2>/dev/null || true
+sleep 1
+pkill -9 -f nginx.local.conf 2>/dev/null || true
+./scripts/cleanup-containers.sh deer-flow-sandbox 2>/dev/null || true
+sleep 1
+
+# ── Banner ────────────────────────────────────────────────────────────────────
+
+echo ""
+echo "=========================================="
+echo " Starting DeerFlow in Daemon Mode"
+echo "=========================================="
+echo ""
+
+# ── Config check ─────────────────────────────────────────────────────────────
+
+if ! { \
+        [ -n "$DEER_FLOW_CONFIG_PATH" ] && [ -f "$DEER_FLOW_CONFIG_PATH" ] || \
+        [ -f backend/config.yaml ] || \
+        [ -f config.yaml ]; \
+    }; then
+    echo "✗ No DeerFlow config file found."
+    echo "  Checked these locations:"
+    echo "    - $DEER_FLOW_CONFIG_PATH (when DEER_FLOW_CONFIG_PATH is set)"
+    echo "    - backend/config.yaml"
+    echo "    - ./config.yaml"
+    echo ""
+    echo "  Run 'make config' from the repo root to generate ./config.yaml, then set required model API keys in .env or your config file."
+    exit 1
+fi
+
+# ── Cleanup on failure ───────────────────────────────────────────────────────
+
+cleanup_on_failure() {
+    echo "Failed to start services, cleaning up..."
+    pkill -f "langgraph dev" 2>/dev/null || true
+    pkill -f "uvicorn src.gateway.app:app" 2>/dev/null || true
+    pkill -f "next dev" 2>/dev/null || true
+    nginx -c "$REPO_ROOT/docker/nginx/nginx.local.conf" -p "$REPO_ROOT" -s quit 2>/dev/null || true
+    sleep 1
+    pkill -9 -f nginx.local.conf 2>/dev/null || true
+    echo "✓ Cleanup complete"
+}
+
+# ── Start services ────────────────────────────────────────────────────────────
+
+mkdir -p logs
+
+echo "Starting LangGraph server..."
+nohup sh -c 'cd backend && NO_COLOR=1 uv run langgraph dev --no-browser --allow-blocking --no-reload > ../logs/langgraph.log 2>&1' &
+sleep 3
+if ! lsof -i :2024 -sTCP:LISTEN -t >/dev/null 2>&1; then
+    echo "✗ LangGraph failed to start. Last log output:"
+    tail -60 logs/langgraph.log
+    cleanup_on_failure
+    exit 1
+fi
+echo "✓ LangGraph server started on localhost:2024"
+
+echo "Starting Gateway API..."
+nohup sh -c 'cd backend && uv run uvicorn src.gateway.app:app --host 0.0.0.0 --port 8001 > ../logs/gateway.log 2>&1' &
+sleep 3
+if ! lsof -i :8001 -sTCP:LISTEN -t >/dev/null 2>&1; then
+    echo "✗ Gateway API failed to start. Last log output:"
+    tail -60 logs/gateway.log
+    cleanup_on_failure
+    exit 1
+fi
+echo "✓ Gateway API started on localhost:8001"
+
+echo "Starting Frontend..."
+nohup sh -c 'cd frontend && pnpm run dev > ../logs/frontend.log 2>&1' &
+sleep 3
+if ! lsof -i :3000 -sTCP:LISTEN -t >/dev/null 2>&1; then
+    echo "✗ Frontend failed to start. Last log output:"
+    tail -60 logs/frontend.log
+    cleanup_on_failure
+    exit 1
+fi
+echo "✓ Frontend started on localhost:3000"
+
+echo "Starting Nginx reverse proxy..."
+nohup sh -c 'nginx -g "daemon off;" -c '"$REPO_ROOT"'/docker/nginx/nginx.local.conf -p '"$REPO_ROOT"' > logs/nginx.log 2>&1' &
+sleep 2
+if ! lsof -i :2026 -sTCP:LISTEN -t >/dev/null 2>&1; then
+    echo "✗ Nginx failed to start. Last log output:"
+    tail -60 logs/nginx.log
+    cleanup_on_failure
+    exit 1
+fi
+echo "✓ Nginx started on localhost:2026"
+
+# ── Ready ─────────────────────────────────────────────────────────────────────
+
+echo ""
+echo "=========================================="
+echo " DeerFlow is running in daemon mode!"
+echo "=========================================="
+echo ""
+echo " 🌐 Application: http://localhost:2026"
+echo " 📡 API Gateway: http://localhost:2026/api/*"
+echo " 🤖 LangGraph: http://localhost:2026/api/langgraph/*"
+echo ""
+echo " 📋 Logs:"
+echo " - LangGraph: logs/langgraph.log"
+echo " - Gateway: logs/gateway.log"
+echo " - Frontend: logs/frontend.log"
+echo " - Nginx: logs/nginx.log"
+echo ""
+echo " 🛑 Stop daemon: make stop"
+echo ""