node: dchain build-tag split -- public build excludes D-Chain + private deps

vms.go drops the dexvm import+entry, calls appendDChainVM; vms_dchain.go (//go:build dchain)
links it, vms_nodchain.go (//go:build !dchain) no-ops; vms/dexvm alias gated //go:build
dchain + doc_nodchain.go placeholder. Genesis-gate (constants.DexVMID, no pkg dep) retained.
VERIFIED: public 'go list -deps ./node/' has ZERO chains/dexvm|luxfi/dex|gpu-kernels|luxcpp;
-tags dchain brings them in. Both builds green.

Consensus change -- held for human review before merge/push (bundles with merkle-activation).

consensus/CLAUDE.md

@@ -0,0 +1,48 @@
+# Consensus Package - AI Assistant Guide
+
+This package is node-side glue around the canonical consensus engine in
+`github.com/luxfi/consensus`. It does NOT implement the protocol — the
+protocol lives in that module.
+
+## Package Structure
+
+- `acceptor.go` - Node-side block-acceptance callbacks (chain-ID-keyed)
+- `quasar/` - Node-side wiring around `consensus/protocol/quasar`
+- `zap/` - ZAP agentic-consensus / DID bridge (self-contained, opt-in)
+
+## Acceptor
+
+`Acceptor` interface called when consensus accepts a block / vertex.
+`AcceptorGroup` manages multiple acceptors per chain — used by the indexer
+and warp IPC. The variant here differs from the canonical
+`luxfi/consensus/core.Acceptor` (different signature: `*runtime.Runtime`
+instead of `context.Context`, plus chain-ID-keyed registration).
+
+## Quasar Wiring
+
+The `quasar/` subpackage wraps `github.com/luxfi/consensus/protocol/quasar`
+with node-specific adapters (P-Chain validator state, BLS signing keys,
+Corona threshold coordinator stub).
+
+### Signature Types
+
+```go
+SignatureTypeBLS      // Classical BLS
+SignatureTypeCorona // Post-quantum threshold
+SignatureTypeQuasar   // Hybrid BLS + Corona
+SignatureTypeMLDSA    // Fallback ML-DSA
+```
+
+## Testing
+
+```bash
+GOWORK=off go test ./consensus/... -v
+```
+
+## Dependencies
+
+- `github.com/luxfi/consensus` - Canonical consensus protocol (engine,
+  protocol/quasar, types, etc.)
+- `github.com/luxfi/ids` - ID types
+- `github.com/luxfi/log` - Logging
+- `github.com/luxfi/runtime` - Runtime context for acceptors

node/vms.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/luxfi/chains/aivm"
 	"github.com/luxfi/chains/bridgevm"
-	"github.com/luxfi/chains/dexvm"
 	"github.com/luxfi/chains/graphvm"
 	"github.com/luxfi/chains/identityvm"
 	"github.com/luxfi/chains/keyvm"
@@ -28,14 +27,18 @@ type vmEntry struct {
 	factory vms.Factory
 }
 
-// registerOptionalVMs registers the 11 optional VMs (A/B/D/G/I/K/O/Q/R/T/Z).
+// registerOptionalVMs registers the optional VMs (A/B/G/I/K/O/Q/R/T/Z).
 // Primary network (P/X/C) is registered separately.
 // Session (S-Chain) is a standalone plugin at github.com/luxfi/session/plugin.
+//
+// The D-Chain (DEXVM) proxy is registered ONLY in the `dchain` build (see
+// vms_dchain.go / vms_nodchain.go): the public OSS luxd MUST NOT even link the
+// proxy/D-Chain tree (public-build purity). appendDChainVM is the seam — a
+// no-op in the default build, the real registration under -tags dchain.
 func (n *Node) registerOptionalVMs() error {
 	entries := []vmEntry{
 		{"AIVM (A-Chain)", aivm.VMID, &aivm.Factory{}},
 		{"BridgeVM (B-Chain)", bridgevm.VMID, &bridgevm.Factory{}},
-		{"DEXVM (D-Chain)", dexvm.VMID, &dexvm.Factory{}},
 		{"GraphVM (G-Chain)", graphvm.VMID, &graphvm.Factory{}},
 		{"IdentityVM (I-Chain)", identityvm.VMID, &identityvm.Factory{}},
 		{"KeyVM (K-Chain)", keyvm.VMID, &keyvm.Factory{}},
@@ -46,6 +49,9 @@ func (n *Node) registerOptionalVMs() error {
 		{"ZKVM (Z-Chain)", zkvm.VMID, &zkvm.Factory{}},
 	}
 
+	// D-Chain proxy VM: linked + appended only under -tags dchain.
+	appendDChainVM(n, &entries)
+
 	registered := 0
 	for _, e := range entries {
 		if err := n.VMManager.RegisterFactory(context.Background(), e.id, e.factory); err != nil {

node/vms_dchain.go

@@ -0,0 +1,22 @@
+// Copyright (C) 2019-2026, Lux Industries Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+//go:build dchain
+
+package node
+
+import "github.com/luxfi/chains/dexvm"
+
+// appendDChainVM links the D-Chain (DEXVM) proxy and appends its factory to the
+// optional-VM registration set. This file compiles ONLY under -tags dchain, so
+// the chains/dexvm import — and the entire proxy/D-Chain tree behind it — is
+// absent from the public OSS luxd binary (public-build purity).
+//
+// Defense in depth: even a dchain-tagged binary will not INSTANTIATE the chain
+// unless D-Chain is present in genesis (the genesis-gate in node.go). Three
+// independent layers gate the venue: public can't link it; venue without
+// D-Chain genesis links-but-doesn't-run it; venue + genesis runs it.
+func appendDChainVM(n *Node, entries *[]vmEntry) {
+	*entries = append(*entries, vmEntry{"DEXVM (D-Chain)", dexvm.VMID, &dexvm.Factory{}})
+	n.Log.Info("D-Chain (DEXVM) proxy linked (dchain build)")
+}

node/vms_nodchain.go

@@ -0,0 +1,13 @@
+// Copyright (C) 2019-2026, Lux Industries Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+//go:build !dchain
+
+package node
+
+// appendDChainVM is a no-op in the public (non-dchain) build: the D-Chain
+// (DEXVM) proxy is NOT linked, so `go build ./...` of luxd does not import
+// github.com/luxfi/chains/dexvm at all and the entire proxy/D-Chain tree is
+// absent from the public binary. The venue build (-tags dchain) links it via
+// vms_dchain.go.
+func appendDChainVM(_ *Node, _ *[]vmEntry) {}

vms/dexvm/dexvm.go

@@ -1,6 +1,8 @@
 // Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
 // See the file LICENSE for licensing terms.
 
+//go:build dchain
+
 // Package dexvm re-exports the canonical DEX VM from
 // github.com/luxfi/chains/dexvm so existing callers that imported
 // github.com/luxfi/node/vms/dexvm pre-extraction keep working
@@ -9,7 +11,11 @@
 // New code should import the canonical path:
 //   "github.com/luxfi/chains/dexvm"
 //
-// This package is a thin alias wrapper kept for backward compatibility.
+// This package is a thin alias wrapper kept for backward compatibility. It is
+// gated behind the `dchain` build tag: it imports github.com/luxfi/chains/dexvm
+// (the D-Chain proxy tree), which MUST be absent from the public OSS luxd build
+// (public-build purity). Nothing in-tree imports this alias; it exists only for
+// out-of-tree backward compatibility, and only a venue (dchain) build links it.
 package dexvm
 
 import (

vms/dexvm/doc_nodchain.go

@@ -0,0 +1,17 @@
+// Copyright (C) 2019-2026, Lux Industries Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+//go:build !dchain
+
+// Package dexvm is, in the public (non-dchain) build, an INTENTIONALLY EMPTY
+// backward-compatibility shim.
+//
+// The real alias (dexvm.go) re-exports github.com/luxfi/chains/dexvm and is
+// gated behind the `dchain` build tag, because importing the D-Chain proxy tree
+// would violate public-build purity (the public OSS luxd must not link
+// chains/dexvm). This file exists only so the package has a buildable Go source
+// in the public build — otherwise `go test ./...` would report "build
+// constraints exclude all Go files" for this directory. Nothing in-tree imports
+// this package; it is kept solely for out-of-tree backward compatibility under
+// a venue (dchain) build.
+package dexvm

vms/platformvm/CLAUDE.md

@@ -0,0 +1,19 @@
+# platformvm
+
+**Org:** luxfi  ·  **Ecosystem:** lux  ·  **Path:** `/Users/a/work/lux/luxfi/platformvm`
+**Origin:** https://github.com/luxfi/platformvm.git
+
+## Discovery
+
+This file (`CLAUDE.md`) is the canonical agent-facing readme; `LLM.md` is a symlink to it. Update either name and both stay in sync.
+
+## Where to look first
+
+- `README.md` — human-facing overview (if present)
+- `package.json` / `Cargo.toml` / `pyproject.toml` / `go.mod` — language & deps
+- `.github/workflows/` — CI surface
+- `docs/` — extended docs (if present)
+
+## Sibling repos
+
+See the org-level `LLM.md` at `/Users/a/work/lux/luxfi/LLM.md` for the full inventory of sibling repos and inter-repo dependencies.

vms/platformvm/LLM.md

@@ -0,0 +1 @@
+CLAUDE.md

vms/xvm/CLAUDE.md

@@ -0,0 +1,19 @@
+# exchangevm
+
+**Org:** luxfi  ·  **Ecosystem:** lux  ·  **Path:** `/Users/a/work/lux/luxfi/exchangevm`
+**Origin:** https://github.com/luxfi/exchangevm.git
+
+## Discovery
+
+This file (`CLAUDE.md`) is the canonical agent-facing readme; `LLM.md` is a symlink to it. Update either name and both stay in sync.
+
+## Where to look first
+
+- `README.md` — human-facing overview (if present)
+- `package.json` / `Cargo.toml` / `pyproject.toml` / `go.mod` — language & deps
+- `.github/workflows/` — CI surface
+- `docs/` — extended docs (if present)
+
+## Sibling repos
+
+See the org-level `LLM.md` at `/Users/a/work/lux/luxfi/LLM.md` for the full inventory of sibling repos and inter-repo dependencies.

vms/xvm/LLM.md

@@ -0,0 +1 @@
+CLAUDE.md