swarm: ctx propagation; bmt fixes; pss generic notification framework (#17150)

* cmd/swarm: minor cli flag text adjustments

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: update description of swarm cmd

* swarm: added network ID test

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* swarm: propagate ctx to internal apis (#754)

* swarm/metrics: collect disk measurements

* swarm/bmt: fix io.Writer interface

  * Write now tolerates arbitrary variable buffers
  * added variable buffer tests
  * Write loop and finalise optimisation
  * refactor / rename
  * add tests for empty input

* swarm/pss: (UPDATE) Generic notifications package (#744)

swarm/pss: Generic package for creating pss notification svcs

* swarm: Adding context to more functions

* swarm/api: change colour of landing page in templates

* swarm/api: change landing page to react to enter keypress

swarm/api/http/error.go

@@ -147,6 +147,14 @@ func Respond(w http.ResponseWriter, req *Request, msg string, code int) {
 	switch code {
 	case http.StatusInternalServerError:
 		log.Output(msg, log.LvlError, l.CallDepth, "ruid", req.ruid, "code", code)
+	case http.StatusMultipleChoices:
+		log.Output(msg, log.LvlDebug, l.CallDepth, "ruid", req.ruid, "code", code)
+		listURI := api.URI{
+			Scheme: "bzz-list",
+			Addr:   req.uri.Addr,
+			Path:   req.uri.Path,
+		}
+		additionalMessage = fmt.Sprintf(`<a href="/%s">multiple choices</a>`, listURI.String())
 	default:
 		log.Output(msg, log.LvlDebug, l.CallDepth, "ruid", req.ruid, "code", code)
 	}