feat: 添加数据模型和存储层

- model: JobTemplate、SubmitJobRequest、JobHistoryQuery 等模型定义

- store: NewGormDB MySQL 连接池，使用 zap 日志替代 GORM 默认日志

- store: TemplateStore CRUD 操作，支持 GORM AutoMigrate

- NewGormDB 接受 gormLevel 参数，由上层传入配置值

- 完整 TDD 测试覆盖

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/store/mysql.go

@@ -0,0 +1,44 @@
+package store
+
+import (
+	"fmt"
+	"time"
+
+	"gcy_hpc_server/internal/logger"
+	"gcy_hpc_server/internal/model"
+
+	"go.uber.org/zap"
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+)
+
+// NewGormDB opens a GORM MySQL connection with sensible defaults.
+func NewGormDB(dsn string, zapLogger *zap.Logger, gormLevel string) (*gorm.DB, error) {
+	gormCfg := &gorm.Config{
+		Logger: logger.NewGormLogger(zapLogger, gormLevel),
+	}
+	db, err := gorm.Open(mysql.Open(dsn), gormCfg)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open gorm mysql: %w", err)
+	}
+
+	sqlDB, err := db.DB()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get underlying sql.DB: %w", err)
+	}
+
+	sqlDB.SetMaxOpenConns(25)
+	sqlDB.SetMaxIdleConns(5)
+	sqlDB.SetConnMaxLifetime(5 * time.Minute)
+
+	if err := sqlDB.Ping(); err != nil {
+		return nil, fmt.Errorf("failed to ping mysql: %w", err)
+	}
+
+	return db, nil
+}
+
+// AutoMigrate runs GORM auto-migration for all models.
+func AutoMigrate(db *gorm.DB) error {
+	return db.AutoMigrate(&model.JobTemplate{})
+}