feat: clean up dead code, update deps, add xvm genesis/fx and genesis builder

Remove unused bloom filter, test helpers, metrics scaffolding, and
linearizable VM wrapper. Trim stale go.sum entries. Add genesis builder
helpers and xvm FX/genesis initialization.

cache/lru/zero.go

@@ -1,9 +0,0 @@
-// Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
-// See the file LICENSE for licensing terms.
-
-package lru
-
-func zero[T any]() T {
-	var z T
-	return z
-}

cache/zero.go

@@ -1,9 +0,0 @@
-// Copyright (C) 2019-2025, Lux Industries Inc. All rights reserved.
-// See the file LICENSE for licensing terms.
-
-package cache
-
-func zero[T any]() T {
-	var z T
-	return z
-}