fix(ci): simplify npm publishing workflow

- Use direct npm publish instead of custom script
- Setup ~/.npmrc in GitHub Actions (standard approach)
- Add smoke test before publishing (--version check)
- Remove complex npmrc creation logic
- Cleaner, more maintainable workflow

Author: moazbuilds

.github/workflows/build-binaries.yml

@@ -66,9 +66,20 @@ jobs:
           name: ${{ matrix.slug }}
           path: binaries/${{ matrix.slug }}
 
+      - name: Setup npm auth
+        if: startsWith(github.ref, 'refs/tags/v')
+        run: |
+          echo "//registry.npmjs.org/:_authToken=${{ secrets.NPM_TOKEN }}" > ~/.npmrc
+
+      - name: Smoke test platform binary
+        shell: bash
+        run: |
+          chmod +x binaries/${{ matrix.slug }}/codemachine* || true
+          binaries/${{ matrix.slug }}/codemachine --version
+
       - name: Publish platform package to npm
         if: startsWith(github.ref, 'refs/tags/v')
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-          CI: true
-        run: bun scripts/publish-platform.mjs --tag latest --access public
+        shell: bash
+        run: |
+          cd binaries/${{ matrix.slug }}
+          npm publish --access public --tag latest