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/api/api.go

@@ -0,0 +1,75 @@
+package api
+
+import (
+	"encoding/json"
+	"nerd-monitor/internal/stats"
+	"nerd-monitor/internal/store"
+	"net/http"
+)
+
+// Handler manages HTTP requests.
+type Handler struct {
+	store *store.Store
+}
+
+// New creates a new API handler.
+func New(s *store.Store) *Handler {
+	return &Handler{store: s}
+}
+
+// ReportStats handles agent stats reports.
+func (h *Handler) ReportStats(w http.ResponseWriter, r *http.Request) {
+	agentID := r.URL.Query().Get("id")
+	if agentID == "" {
+		http.Error(w, "missing agent id", http.StatusBadRequest)
+		return
+	}
+
+	var stat stats.Stats
+	if err := json.NewDecoder(r.Body).Decode(&stat); err != nil {
+		http.Error(w, "invalid request body", http.StatusBadRequest)
+		return
+	}
+
+	h.store.UpdateAgent(agentID, &stat)
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
+}
+
+// GetAgent returns stats for a single agent.
+func (h *Handler) GetAgent(w http.ResponseWriter, r *http.Request) {
+	agentID := r.URL.Query().Get("id")
+	if agentID == "" {
+		http.Error(w, "missing agent id", http.StatusBadRequest)
+		return
+	}
+
+	agent := h.store.GetAgent(agentID)
+	if agent == nil {
+		http.Error(w, "agent not found", http.StatusNotFound)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(agent)
+}
+
+// ListAgents returns all agents.
+func (h *Handler) ListAgents(w http.ResponseWriter, r *http.Request) {
+	agents := h.store.GetAllAgents()
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(agents)
+}
+
+// DeleteAgent removes an agent.
+func (h *Handler) DeleteAgent(w http.ResponseWriter, r *http.Request) {
+	agentID := r.URL.Query().Get("id")
+	if agentID == "" {
+		http.Error(w, "missing agent id", http.StatusBadRequest)
+		return
+	}
+
+	h.store.DeleteAgent(agentID)
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(map[string]string{"status": "deleted"})
+}