fix(ci): revert publish runner to ubuntu-latest for npm OIDC

macOS runner breaks npm OIDC trusted publishing. Bun can cross-compile
all platform binaries on ubuntu, so macOS runner is not needed.

.github/workflows/publish.yml

@@ -60,7 +60,7 @@ jobs:
         run: bun run typecheck
 
   publish:
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     needs: [test, typecheck]
     if: github.repository == 'code-yeongyu/oh-my-opencode'
     steps:
@@ -77,11 +77,13 @@ jobs:
       - uses: actions/setup-node@v4
         with:
           node-version: "24"
-          registry-url: "https://registry.npmjs.org"
 
       - name: Upgrade npm for OIDC trusted publishing
         run: npm install -g npm@latest
 
+      - name: Configure npm registry
+        run: npm config set registry https://registry.npmjs.org
+
       - name: Install dependencies
         run: bun install
         env: