Fix zero UUID and storage metrics issues\n\n- Add ID generation in signAndCreateCommand to prevent zero UUIDs\n- Fix storage metrics metadata field (remove pq.Array)\n- Add IdempotencyKey field to AgentCommand model\n\nThese issues were causing duplicate key violations and storage page errors.

aggregator-server/internal/api/handlers/subsystems.go

@@ -32,6 +32,19 @@ func NewSubsystemHandler(sq *queries.SubsystemQueries, cq *queries.CommandQuerie
 
 // signAndCreateCommand signs a command if signing service is enabled, then stores it in the database
 func (h *SubsystemHandler) signAndCreateCommand(cmd *models.AgentCommand) error {
+	// Generate ID if not set (prevents zero UUID issues)
+	if cmd.ID == uuid.Nil {
+		cmd.ID = uuid.New()
+	}
+
+	// Set timestamps if not set
+	if cmd.CreatedAt.IsZero() {
+		cmd.CreatedAt = time.Now()
+	}
+	if cmd.UpdatedAt.IsZero() {
+		cmd.UpdatedAt = time.Now()
+	}
+
 	// Sign the command before storing
 	if h.signingService != nil && h.signingService.IsEnabled() {
 		signature, err := h.signingService.SignCommand(cmd)