fix(rustffi): forward the node identity key regardless of enableSigning (#1603)

The wrapper only handed the node identity key to the FFI node when enableSigning was
true, so an FFI node started with signing disabled had no P2P/KMS identity and a
peer's KMS denied it on a registered branchable-collection object. Go sets the node
identity at construction independently of signing (cbindings/node_new.go); do the same.

Author: edjroz

tests/clients/rustffi/wrapper.go

@@ -358,8 +358,10 @@ func NewWrapper(
 		opts.InMemory = true
 	}
 
-	// If signing is enabled and we have a full identity with a private key, use it
-	if enableSigning && nodeIdentity != nil {
+	// Go configures the node identity at construction independently of block
+	// signing; the Rust node derives its P2P and KMS identity from this key.
+	// EnableSigning stays a separate flag.
+	if nodeIdentity != nil {
 		if fullIdent, ok := nodeIdentity.(identity.FullIdentity); ok {
 			privKey := fullIdent.PrivateKey()
 			opts.SigningKeyType = string(privKey.Type())
@@ -496,8 +498,10 @@ func NewWrapperWithP2P(
 		opts.InMemory = true
 	}
 
-	// If signing is enabled and we have a full identity with a private key, use it
-	if enableSigning && nodeIdentity != nil {
+	// Go configures the node identity at construction independently of block
+	// signing; the Rust node derives its P2P and KMS identity from this key.
+	// EnableSigning stays a separate flag.
+	if nodeIdentity != nil {
 		if fullIdent, ok := nodeIdentity.(identity.FullIdentity); ok {
 			privKey := fullIdent.PrivateKey()
 			opts.SigningKeyType = string(privKey.Type())