feat: init pc-monitor project

- Client: Go-based Windows hardware monitoring (CPU, GPU, memory, disk, network, power)
- Server: Go + Gin + SQLite backend with REST API
- Frontend: Vue 3 + Element Plus dashboard
- Docker deployment support
- Windows service installation script

server/model/device.go

@@ -0,0 +1,13 @@
+package model
+
+import "time"
+
+type Device struct {
+	ID           string    `json:"id"`
+	Hostname     string    `json:"hostname"`
+	OS           string    `json:"os"`
+	IP           string    `json:"ip"`
+	RegisteredAt time.Time `json:"registered_at"`
+	LastReportAt time.Time `json:"last_report_at"`
+	Status       string    `json:"status"`
+}