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>

server.go

@@ -98,6 +98,10 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("PUT /api/admin/settings", s.withServerAdmin(s.putSettings))
 	mux.HandleFunc("POST /api/admin/settings/test-mail", s.withServerAdmin(s.testMail))
 	mux.HandleFunc("GET /api/admin/update", s.withServerAdmin(s.checkUpdate))
+	mux.HandleFunc("POST /api/admin/update/apply", s.withServerAdmin(s.applyUpdate))
+	mux.HandleFunc("GET /api/versions", s.withUser(s.latestVersions))
+	mux.HandleFunc("POST /api/edges/{id}/update", s.withServerAdmin(s.updateEdge))
+	mux.HandleFunc("POST /api/orgs/{org}/sites/{id}/update", s.withOrg(true, s.updateSite))
 	mux.HandleFunc("GET /api/admin/audit", s.withServerAdmin(func(w http.ResponseWriter, r *http.Request, p *principal) {
 		writeJSON(w, 200, s.logs.queryAudit("", 300, 0))
 	}))