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/gpu.go

@@ -0,0 +1,80 @@
+package collector
+
+import (
+	"encoding/json"
+	"os/exec"
+	"strings"
+)
+
+type GPUInfo struct {
+	Usage       float64 `json:"usage"`
+	Temperature float64 `json:"temperature"`
+	MemoryTotal uint64  `json:"memory_total"`
+	MemoryUsed  uint64  `json:"memory_used"`
+	Name        string  `json:"name"`
+}
+
+type nvidiaSMIOutput struct {
+	GPUs []struct {
+		Name         string `json:"name"`
+		Utilization  struct {
+			GPU string `json:"gpu"`
+		} `json:"utilization"`
+		Temperature struct {
+			GPU string `json:"gpu_temp"`
+		} `json:"temperature"`
+		Memory struct {
+			Total string `json:"total"`
+			Used  string `json:"used"`
+		} `json:"fb_memory_usage"`
+	} `json:"gpus"`
+}
+
+func CollectGPU() (*GPUInfo, error) {
+	// Try NVIDIA GPU first
+	info, err := collectNvidiaGPU()
+	if err == nil && info != nil {
+		return info, nil
+	}
+
+	// Return empty GPU info if no GPU detected
+	return &GPUInfo{
+		Name: "No GPU detected",
+	}, nil
+}
+
+func collectNvidiaGPU() (*GPUInfo, error) {
+	cmd := exec.Command("nvidia-smi", "--query-gpu=name,utilization.gpu,temperature.gpu,memory.total,memory.used", "--format=csv,noheader,nounits")
+	output, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+
+	lines := strings.Split(strings.TrimSpace(string(output)), "\n")
+	if len(lines) == 0 {
+		return nil, nil
+	}
+
+	fields := strings.Split(lines[0], ",")
+	if len(fields) < 5 {
+		return nil, nil
+	}
+
+	info := &GPUInfo{
+		Name: strings.TrimSpace(fields[0]),
+	}
+
+	// Parse values (ignore errors, use defaults)
+	var usage, temp, memTotal, memUsed float64
+	json.Unmarshal([]byte(strings.TrimSpace(fields[1])), &usage)
+	json.Unmarshal([]byte(strings.TrimSpace(fields[2])), &temp)
+	json.Unmarshal([]byte(strings.TrimSpace(fields[3])), &memTotal)
+	json.Unmarshal([]byte(strings.TrimSpace(fields[4])), &memUsed)
+
+	info.Usage = usage
+	info.Temperature = temp
+	info.MemoryTotal = uint64(memTotal) * 1024 * 1024 // Convert MB to bytes
+	info.MemoryUsed = uint64(memUsed) * 1024 * 1024
+
+	return info, nil
+}