Description

Align release infrastructure with mcp-trino's working patterns.

Updated files:

• Dockerfile - Simplified for GoReleaser's dockers_v2 (uses linux/${TARGETARCH}/mcp-s3)
• mcpb/build.sh - Rewritten to match mcp-trino (supports --use-dist flag)
• mcpb/manifest.json - Updated to manifest_version 0.3 format with proper user_config
• server.json - Updated to MCP Registry schema with PLACEHOLDER_SHA256 pattern
• .github/workflows/release.yml - Complete rewrite matching mcp-trino's workflow
• .goreleaser.yml - Use HOMEBREW_TAP_GITHUB_TOKEN env var, removed skip_upload: auto

Root cause of previous failures:

1. Dockerfile tried multi-stage build, but GoReleaser's dockers_v2 only provides pre-built binaries
2. mcpb/build.sh didn't support --use-dist flag needed in CI
3. release.yml had wrong mcp-publisher install and server.json preparation steps
4. .goreleaser.yml used wrong env var name for Homebrew token

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• Test improvement (new or updated tests)
• Documentation update
• Stability/performance improvement
• Build/CI improvement

Note: New features are developed by maintainers only. See CONTRIBUTING.md for details.

Related Issues

Fixes release workflow failures:

• https://github.com/txn2/mcp-s3/actions/runs/21107945111
• https://github.com/txn2/mcp-s3/actions/runs/21108334239

Testing

• goreleaser check passes
• All files match mcp-trino's working patterns

Checklist

• My code follows the project's style guidelines (make lint)
• I have read CONTRIBUTING.md
• This PR is focused and does not include unrelated changes