perf(agent): cache ListAgentIDs() result before MCP tool registration loop

ListAgentIDs() was called on every iteration of the inner tool loop,
causing repeated allocations. Capture the slice once and reuse it for
both agentCount and the registration loop.

pkg/agent/loop.go

@@ -185,12 +185,13 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 			servers := mcpManager.GetServers()
 			uniqueTools := 0
 			totalRegistrations := 0
-			agentCount := len(al.registry.ListAgentIDs())
+			agentIDs := al.registry.ListAgentIDs()
+			agentCount := len(agentIDs)
 
 			for serverName, conn := range servers {
 				uniqueTools += len(conn.Tools)
 				for _, tool := range conn.Tools {
-					for _, agentID := range al.registry.ListAgentIDs() {
+					for _, agentID := range agentIDs {
 						agent, ok := al.registry.GetAgent(agentID)
 						if !ok {
 							continue