Show edge and site versions with Update buttons; Update now for Hammerhead itself

Edges and sites report their version and whether auto-update is on. Hammerhead can ask a machine that
has auto-update on to install the newest release, and shows the outcome. Requests carry an ID so a
stale result can't answer a new one.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

infra.go

@@ -24,6 +24,11 @@ type edgeView struct {
 	TunnelAddr string   `json:"tunnelAddr,omitempty"`
 	Token      string   `json:"token,omitempty"`
 	OrgIDs     []string `json:"orgIds,omitempty"`
+
+	Version       string `json:"version,omitempty"`
+	AutoUpdate    bool   `json:"autoUpdate,omitempty"`
+	UpdatePending bool   `json:"updatePending,omitempty"`
+	UpdateMsg     string `json:"updateMsg,omitempty"`
 }
 
 func (s *Server) viewEdge(e *model.Edge, admin bool) edgeView {
@@ -33,6 +38,7 @@ func (s *Server) viewEdge(e *model.Edge, admin bool) edgeView {
 	}
 	if admin {
 		v.TunnelAddr, v.Token, v.OrgIDs = e.TunnelAddr, e.Token, e.OrgIDs
+		v.Version, v.AutoUpdate, v.UpdatePending, v.UpdateMsg = e.Version, e.AutoUpdate, e.UpdateID != "", e.UpdateMsg
 		if v.OrgIDs == nil {
 			v.OrgIDs = []string{}
 		}