docs: update development and release instructions

[satsukies]

Summary

Fix outdated development and release instructions in CONTRIBUTING.md, and complete the "How a release happens" steps in the README.

• CONTRIBUTING.md
  • Development commands now match package.json: npm run build is tsc only, and npm run bundle builds the bundle. The bundle may be built locally but must never be committed (a pre-commit hook blocks it).
  • The CI description now covers Node 24 and the bundle-compat job on Node 20.0.0.
  • Replace "when you bump the version, update all three together" with: versions are bumped by release-please in the release PR, so do not bump them manually. The consistency tests catch mismatched manual edits, and they cover both plugin.json files, the marketplace entry and the release-please manifest.
  • Note that PR titles must follow Conventional Commits because they become the squash-merge commit titles, and link to the README "Releasing" section.
• README "How a release happens"
  • Add the step where the Release workflow regenerates and commits plugin/scripts/bundle.js on the release PR.
  • Note that plugin users can pick up the release once the release PR lands on main.
  • Add the npm publish of @deploygate/mcp after the tag and GitHub Release.
  • The README change is limited to that list. Allow retrying npm publish for an existing release tag #82 adds a separate subsection at the end of "Releasing", so the two PRs don't conflict.

Related Issue

Closes #83

Type of change

• Bug fix
• New feature
• Documentation
• Refactor / internal change
• Build / CI / tooling

Test plan

• npm run build passes
• npm test passes (235 tests)
• Manually verified the change (describe how below)

Every statement was checked against package.json, .githooks/pre-commit, .github/workflows/ci.yml, .github/workflows/release.yml, .release-please-config.json and src/__tests__/plugin.test.ts.

Checklist

• I have updated the plugin version in plugin/.codex-plugin/plugin.json and plugin/.claude-plugin/plugin.json if applicable (not applicable: docs only)
• I have read and agree to the Code of Conduct

🤖 Generated with Claude Code

---

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

[Copilot]

Copilot review overview

🟢 Approval recommended

The documentation accurately reflects the referenced scripts, tests, hooks, and workflows.

Review effort: Balanced
Findings: None

What changed in this PR

Updates contributor and release documentation to match the repository’s current build, CI, versioning, and publishing workflows.

Changes:

• Clarifies development commands, CI environments, and bundle handling.
• Documents Conventional Commit titles and release-please versioning.
• Completes the automated release sequence, including bundle regeneration and npm publishing.

File	Description
README.md	Documents the complete release workflow.
CONTRIBUTING.md	Corrects development, CI, PR, and versioning guidance.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.