created device config, created new UI elements in device dashboard

server/internal/models/device_config.go

@@ -0,0 +1,19 @@
+package models
+
+import "time"
+
+// One-to-one config bound to a device GUID.
+type DeviceConfig struct {
+	DeviceGUID string `gorm:"primaryKey;size:64"` // 1:1 with Device.GUID
+	// Fields reflect your device JSON keys (m_*)
+	MGuid              string `gorm:"size:64;not null"` // duplicate for device FW convenience
+	MRecordingDuration int    `gorm:"not null;default:240"`
+	MBaseURL           string `gorm:"size:512;not null"`
+	MPolling           int    `gorm:"not null;default:30"`
+	MJitter            int    `gorm:"not null;default:10"`
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+
+	Device Device `gorm:"constraint:OnDelete:CASCADE;foreignKey:DeviceGUID;references:GUID"`
+}