Open every link with no signer instead of following the controller's key

The controller that signed the hand-over, search, judgement, access and move asks ended (issue 1126), so a link
believes none of them by having no signer, and the per-ask key it was told to follow goes with the lease.

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

cmd/mesh-host/main.go

@@ -1120,9 +1120,6 @@ func runLink(ctx context.Context, opts options) error {
 		Membership: membership,
 		// And the public halves and certificate its record says (novox/hq ADR 0555 §3), read at each facts report.
 		Keys: recordKeys(opts.state, trust.Trusts),
-		// And no controller's key: every ask the controller would sign is refused, never verified with the membership's
-		// signer (novox/hq ADR 0563 §7; issue 1126, the controller ended by its unassignment).
-		ControllerKey: noControllerKey,
 		// And the first have this build writes is what proves it to the launcher (ADR 0539 §9, ADR 0227 §8).
 		HaveWritten: proof.haveWritten,
 		// And the operator's hand-over of a directory used as found, carried by the controller from the

cmd/mesh-host/trust.go

@@ -36,10 +36,6 @@ type meshTrust struct {
 // newMeshTrust trusts nothing until the vault's key is read.
 func newMeshTrust() *meshTrust { return &meshTrust{} }
 
-// noControllerKey is the controller's key as this engine trusts it: none. A link told it refuses every ask signed as
-// the controller's, where a link told nothing would verify it with the membership's signer (link.HandOverCheck).
-func noControllerKey() ed25519.PublicKey { return nil }
-
 // onChange names who is told when what it trusts changed.
 func (t *meshTrust) onChange(f func()) {
 	t.mu.Lock()