v0.4.0 — Coding-agent MCP integration

What's Changed

• Add trusted PyPI publishing by @Mandolaro in #5
• Document PyPI installation by @Mandolaro in #6
• Validate custom skill install targets by @Mandolaro in #7
• Add structured contributor issue forms by @Mandolaro in #8
• Add stateless coding-agent MCP integration by @Mandolaro in #9

Full Changelog: v0.3.0...v0.4.0