Initial commit: Nerd Monitor - Cross-platform system monitoring application

Features:
- Multi-platform agents (Linux, macOS, Windows - AMD64 & ARM64)
- Real-time CPU, RAM, and disk usage monitoring
- Responsive web dashboard with live status indicators
- Session-based authentication with secure credentials
- Stale agent detection and removal (6+ months inactive)
- Auto-refresh dashboard (5 second intervals)
- 15-second agent reporting intervals
- Auto-generated agent IDs from hostnames
- In-memory storage (zero database setup)
- Minimal dependencies (Chi router + Templ templating)

Project Structure:
- cmd/: Agent and Server executables
- internal/: API, Auth, Stats, Storage, and UI packages
- views/: Templ templates for dashboard UI
- Makefile: Build automation for all platforms

Ready for deployment with comprehensive documentation:
- README.md: Full project documentation
- QUICKSTART.md: Getting started guide
- AGENTS.md: Development guidelines

internal/stats/stats.go

@@ -0,0 +1,67 @@
+package stats
+
+import (
+	"runtime"
+	"time"
+
+	"github.com/shirou/gopsutil/v3/cpu"
+	"github.com/shirou/gopsutil/v3/disk"
+	"github.com/shirou/gopsutil/v3/mem"
+)
+
+// Stats represents system statistics.
+type Stats struct {
+	CPUUsage  float64   `json:"cpu_usage"`
+	RAMUsage  uint64    `json:"ram_usage"`
+	RAMTotal  uint64    `json:"ram_total"`
+	DiskUsage uint64    `json:"disk_usage"`
+	DiskTotal uint64    `json:"disk_total"`
+	Timestamp time.Time `json:"timestamp"`
+	Hostname  string    `json:"hostname"`
+}
+
+// Collector gathers system statistics.
+type Collector struct{}
+
+// NewCollector creates a new stats collector.
+func NewCollector() *Collector {
+	return &Collector{}
+}
+
+// Collect gathers current system statistics.
+func (c *Collector) Collect(hostname string) (*Stats, error) {
+	cpuPercent, err := cpu.Percent(time.Second, false)
+	if err != nil {
+		return nil, err
+	}
+
+	memStats, err := mem.VirtualMemory()
+	if err != nil {
+		return nil, err
+	}
+
+	diskStats, err := disk.Usage("/")
+	if err != nil {
+		return nil, err
+	}
+
+	var cpuUsage float64
+	if len(cpuPercent) > 0 {
+		cpuUsage = cpuPercent[0]
+	}
+
+	return &Stats{
+		CPUUsage:  cpuUsage,
+		RAMUsage:  memStats.Used,
+		RAMTotal:  memStats.Total,
+		DiskUsage: diskStats.Used,
+		DiskTotal: diskStats.Total,
+		Timestamp: time.Now(),
+		Hostname:  hostname,
+	}, nil
+}
+
+// GetNumCores returns the number of CPU cores.
+func GetNumCores() int {
+	return runtime.NumCPU()
+}