fix: PM2启动脚本优化 - 自动清理旧进程和支持多版本PostgreSQL

改进：
1. 自动清理端口8028的旧后端进程（start_app.sh遗留）
2. 清理旧的前端PID文件
3. 支持检测PostgreSQL@15/14而不仅是@16
4. 添加cleanup_old_processes步骤避免端口冲突

修复问题：
- "Address already in use" 错误
- 多次重启失败

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

start_with_pm2.sh

@@ -45,16 +45,22 @@ check_pm2() {
 start_databases() {
     print_step "Starting databases..."
 
-    # PostgreSQL
-    if brew services list | grep postgresql@16 | grep started >/dev/null 2>&1; then
+    # PostgreSQL - 检测任意版本
+    if lsof -i :5432 -sTCP:LISTEN -t >/dev/null 2>&1; then
         print_msg "PostgreSQL already running"
     else
-        brew services start postgresql@16
-        print_success "PostgreSQL started"
+        # 尝试启动已安装的任意PostgreSQL版本
+        for pg_ver in postgresql@16 postgresql@15 postgresql@14 postgresql; do
+            if brew services list | grep "$pg_ver" >/dev/null 2>&1; then
+                brew services start "$pg_ver"
+                print_success "PostgreSQL started ($pg_ver)"
+                break
+            fi
+        done
     fi
 
     # Redis
-    if brew services list | grep redis | grep started >/dev/null 2>&1; then
+    if lsof -i :6379 -sTCP:LISTEN -t >/dev/null 2>&1; then
         print_msg "Redis already running"
     else
         brew services start redis
@@ -70,13 +76,34 @@ setup_logs() {
     print_success "Log directory created"
 }
 
+# 清理旧进程
+cleanup_old_processes() {
+    print_step "Cleaning up old processes..."
+
+    # 清理旧的非PM2后端进程（可能来自start_app.sh）
+    if lsof -ti :8028 >/dev/null 2>&1; then
+        print_msg "Killing old backend processes on port 8028"
+        lsof -ti :8028 | xargs kill -9 2>/dev/null || true
+        sleep 1
+    fi
+
+    # 清理旧的非PM2前端进程
+    if [ -f ".frontend.pid" ]; then
+        print_msg "Killing old frontend process"
+        kill $(cat .frontend.pid) 2>/dev/null || true
+        rm -f .frontend.pid
+    fi
+
+    # 停止旧的PM2进程（如果存在）
+    pm2 delete ljwx-stock-frontend ljwx-stock-backend 2>/dev/null || true
+
+    print_success "Old processes cleaned"
+}
+
 # 启动应用
 start_apps() {
     print_step "Starting applications with PM2..."
 
-    # 停止旧的进程（如果存在）
-    pm2 delete ljwx-stock-frontend ljwx-stock-backend 2>/dev/null || true
-
     # 使用 PM2 启动
     pm2 start ecosystem.config.js
 
@@ -116,6 +143,7 @@ main() {
     check_pm2
     start_databases
     setup_logs
+    cleanup_old_processes
     start_apps
     show_status