Add logging and fix /agents/ route error

internal/store/store.go

@@ -2,6 +2,7 @@ package store
 
 import (
 	"errors"
+	"log/slog"
 	"sync"
 	"time"
 
@@ -53,6 +54,7 @@ func (s *Store) UpdateAgent(id string, stat *stats.Stats) {
 		DiskTotal: stat.DiskTotal,
 		LastSeen:  time.Now(),
 	}
+	slog.Debug("Agent stats updated", "agentID", id, "hostname", stat.Hostname, "cpu", stat.CPUUsage)
 }
 
 // GetAgent retrieves agent stats by ID.
@@ -60,7 +62,13 @@ func (s *Store) GetAgent(id string) *AgentStats {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	return s.agents[id]
+	agent := s.agents[id]
+	if agent != nil {
+		slog.Debug("Agent retrieved", "agentID", id, "hostname", agent.Hostname)
+	} else {
+		slog.Debug("Agent not found", "agentID", id)
+	}
+	return agent
 }
 
 // GetAllAgents returns all agents.
@@ -72,6 +80,7 @@ func (s *Store) GetAllAgents() []*AgentStats {
 	for _, agent := range s.agents {
 		agents = append(agents, agent)
 	}
+	slog.Debug("All agents retrieved", "count", len(agents))
 	return agents
 }
 
@@ -81,6 +90,7 @@ func (s *Store) DeleteAgent(id string) {
 	defer s.mu.Unlock()
 
 	delete(s.agents, id)
+	slog.Debug("Agent deleted", "agentID", id)
 }
 
 // UpdateHostname updates the hostname for an agent.
@@ -90,9 +100,11 @@ func (s *Store) UpdateHostname(id string, hostname string) error {
 
 	agent, exists := s.agents[id]
 	if !exists {
+		slog.Debug("Agent not found for hostname update", "agentID", id)
 		return ErrAgentNotFound
 	}
 
 	agent.Hostname = hostname
+	slog.Debug("Agent hostname updated", "agentID", id, "hostname", hostname)
 	return nil
 }