fix: Add scope and update npm for OIDC publishing

- Added scope: "@valknarthing" to setup-node action (required for scoped packages)
- Added npm update step to ensure npm CLI v11.5.1+ (required for OIDC support)

Matches the original OpenAI Codex workflow configuration.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/rust-release.yml

@@ -493,6 +493,10 @@ jobs:
         with:
           node-version: 22
           registry-url: "https://registry.npmjs.org"
+          scope: "@valknarthing"
+
+      - name: Update npm
+        run: npm install -g npm@latest
 
       - name: Download npm tarballs from release
         env: