feat: sync current progress (P0 hardening + P1 observability + deploy docs/systemd)

internal/model/user.go

@@ -0,0 +1,12 @@
+package model
+
+import "time"
+
+type User struct {
+	ID           uint      `json:"id" gorm:"primaryKey"`
+	Username     string    `json:"username" gorm:"size:64;uniqueIndex;not null"`
+	PasswordHash string    `json:"-" gorm:"size:255;not null"`
+	Timezone     string    `json:"timezone" gorm:"size:64;not null;default:UTC"`
+	CreatedAt    time.Time `json:"created_at"`
+	UpdatedAt    time.Time `json:"updated_at"`
+}