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

client/collector/memory.go

@@ -0,0 +1,24 @@
+package collector
+
+import (
+	"github.com/shirou/gopsutil/v3/mem"
+)
+
+type MemoryInfo struct {
+	Total uint64  `json:"total"`
+	Used  uint64  `json:"used"`
+	Usage float64 `json:"usage"`
+}
+
+func CollectMemory() (*MemoryInfo, error) {
+	vmStat, err := mem.VirtualMemory()
+	if err != nil {
+		return nil, err
+	}
+
+	return &MemoryInfo{
+		Total: vmStat.Total,
+		Used:  vmStat.Used,
+		Usage: vmStat.UsedPercent,
+	}, nil
+}