feat(rvf-node): ANN-across-branch native binary + publish 0.2.0

Rebuild linux-x64-gnu .node binary from rvf-runtime with PRs #617
(queryable COW branches) + #618 (ANN-across-branch dual-graph merge).

- @ruvector/rvf-node-linux-x64-gnu: 0.1.7→0.2.0 (1507kB .node, built release)
- @ruvector/rvf-node: 0.1.7→0.2.0 (optionalDep linux-x64-gnu bumped to 0.2.0)

RvfDatabase.branch() (already exposed in napi) + query() now transparently
routes COW children through query_via_index_cow (dual-graph HNSW merge).
recall@10 = 1.0000 verified via JS smoke test. Darwin/win32/arm64 platform
packages remain at 0.1.7 pending CI cross-compilation.

Co-Authored-By: claude-flow <ruv@ruv.net>
Claude-Session: https://claude.ai/code/session_019rVRYrRDKyxYK18kuVrDSf

crates/rvf/rvf-node/npm/linux-x64-gnu/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ruvector/rvf-node-linux-x64-gnu",
-  "version": "0.1.7",
+  "version": "0.2.0",
   "cpu": [
     "x64"
   ],

npm/packages/rvf-node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ruvector/rvf-node",
-  "version": "0.1.7",
+  "version": "0.2.0",
   "description": "RuVector Format Node.js native bindings",
   "main": "index.js",
   "types": "index.d.ts",
@@ -35,7 +35,7 @@
     "access": "public"
   },
   "optionalDependencies": {
-    "@ruvector/rvf-node-linux-x64-gnu": "0.1.7",
+    "@ruvector/rvf-node-linux-x64-gnu": "0.2.0",
     "@ruvector/rvf-node-darwin-x64": "0.1.7",
     "@ruvector/rvf-node-darwin-arm64": "0.1.7",
     "@ruvector/rvf-node-win32-x64-msvc": "0.1.7",