v0.6.1 — npm listing + publish pipeline fixes

Fixed

• The npm description now fits npm's 255-character limit. The 0.6.0 text was
  381 characters, so npm search cut it off mid-word and dropped "Claude Code
  plugin", "MCP Registry" and "zero dependencies".
• publish.yml: a Trusted publishing preflight step runs the OIDC exchange
  and prints why npm rejects it. Before this, npm fell back to NPM_TOKEN and
  reported only E404 PUT. The MCP Registry step now waits until npm serves
  the new version: npm processes a fresh release for a few minutes, and
  registering before that fails with "version not found".
• CONTRIBUTING: the npm trusted-publisher setup needs your 2FA security key,
  and Allow npm publish must be ticked (only npm stage publish is
  allowed by default).

Workflow v3, the Claude Code plugin and the MCP Registry listing shipped in v0.6.0.

Full changelog: v0.6.0...v0.6.1