server: Go 服务器（REST+WSS 网关+JWT+Argon2+配对+素材直链+任务状态机）；修复并发下线 send-on-closed-channel、下发查询 SQL 优先级、配对码原子占用、上传体积上限、JWT 默认密钥告警

server/internal/db/db.go

@@ -0,0 +1,53 @@
+package db
+
+import (
+	"fmt"
+	"time"
+
+	"everypublish/server/internal/config"
+	"everypublish/server/internal/models"
+
+	gormmysql "gorm.io/driver/mysql"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+// Connect 建立 MySQL 连接并 Ping（重试 10 次，适配容器冷启动）
+func Connect(cfg *config.Config) (*gorm.DB, error) {
+	db, err := gorm.Open(gormmysql.Open(cfg.MySQLDSN), &gorm.Config{Logger: logger.Default.LogMode(logger.Warn)})
+	if err != nil {
+		return nil, err
+	}
+	sqlDB, err := db.DB()
+	if err != nil {
+		return nil, err
+	}
+	sqlDB.SetMaxOpenConns(50)
+	sqlDB.SetMaxIdleConns(10)
+	sqlDB.SetConnMaxLifetime(time.Hour)
+	for i := 0; i < 10; i++ {
+		if err = sqlDB.Ping(); err == nil {
+			return db, nil
+		}
+		time.Sleep(time.Second)
+	}
+	return nil, fmt.Errorf("mysql ping failed: %w", err)
+}
+
+// AutoMigrate 开发期建表；生产走 golang-migrate（db/migrations）
+func AutoMigrate(db *gorm.DB) error {
+	return db.AutoMigrate(
+		&models.User{},
+		&models.Workspace{},
+		&models.Member{},
+		&models.Account{},
+		&models.Material{},
+		&models.Task{},
+		&models.AgentDevice{},
+		&models.Challenge{},
+		&models.AuditLog{},
+		&models.Notification{},
+		&models.PairingCode{},
+		&models.TransferToken{},
+	)
+}