fix: Make GitHub release creation non-blocking in workflows

- Add continue-on-error to GitHub release step
- Prevents workflow failure when GITHUB_TOKEN lacks permissions
- PyPI publish still succeeds even if GitHub release fails

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

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

.github/workflows/release-manual.yml

@@ -231,6 +231,7 @@ jobs:
 
       - name: Create GitHub Release
         uses: softprops/action-gh-release@v1
+        continue-on-error: true  # Don't fail if GitHub release creation fails
         with:
           tag_name: ${{ needs.validate.outputs.tag_name }}
           name: Release v${{ github.event.inputs.version }}

.github/workflows/release.yml

@@ -235,6 +235,7 @@ jobs:
 
       - name: Create GitHub Release
         uses: softprops/action-gh-release@v1
+        continue-on-error: true  # Don't fail if GitHub release creation fails
         with:
           tag_name: ${{ needs.validate-and-tag.outputs.tag_name }}
           name: Release v${{ github.event.inputs.version }}