Remove what only served the controller's compositions: the own-secret resync, the shadow's wants watch and the vault key's follower

Every node composes its own since group A (issue 1126), so the resync that handed the vault an own secret's value
while a node applied the controller's compositions never runs, the shadow's answers read no want, and nothing follows
the heard vault key any more.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

cmd/mesh-host/nodeagent.go

@@ -648,14 +648,9 @@ func nodeAgent(ctx context.Context, opts options, signer ed25519.PublicKey, trus
 		shadowHooks := hooks
 		shadowHooks.refused, shadowHooks.certify = nil, nil
 		shadowEnv := composerEnv(session, node, say, shadowHooks)
-		// And, after each answer, what runs of an own secret the answer says the vault holds another value of: handed to
-		// the vault only while a node applied the controller's compositions (issue 1126, cause C4; ownresync), so nothing now.
-		composes := &composesNow{}
-		resync := ownResync(session, node, say, shadowEnv, composes)
 		shadow := selfcompose.NewShadow(shadowEnv,
 			func(ctx context.Context, answers map[string]delivery.CandidateAnswer) {
 				session.NoteCandidates(ctx, delivery.WithValuesDiffer(answers))
-				go resync.take(ctx, answers)
 			})
 		go shadow.Keep(run, link.Backoff) // this run's alone: a switch begins a run, and its shadow, again
 		// Its own composer, always (issue 1126, A7): a composition made elsewhere (the controller's, in the node's
@@ -664,7 +659,6 @@ func nodeAgent(ctx context.Context, opts options, signer ed25519.PublicKey, trus
 		composer := selfComposer(session, node, hooks, say)
 		machinesNow.Store(composer) // the machines a failing network part points at, by the placements (issue 774)
 		composerNow.Store(composer) // what the verb compose asks a pass of, this run's alone
-		composes.set(delivery.ComposesOwn)
 		env.Composed, env.SelfComposed, env.Policy = composer, true, composer.Policy
 		env.HoldsData = composer.HoldsData // what runs from the kept declaration says Data as its manifest does
 		session.NoteComposes(linked, delivery.ComposesOwn, "it composes its own modules, and applies no composition made elsewhere")