feat: automated changelog via commit-and-tag-version

[OneStepAt4time]

Feature Request — Automated Changelog Generation

Context

Hep currently writes CHANGELOG.md manually on every release. Aegis already uses conventional commits (feat:, fix:, chore:, etc.) — this means commit-and-tag-version can automate 100% of the changelog + version bump + tag process.

What to build

• Install commit-and-tag-version as devDependency
• Add .versionrc.json config (types to include, output format)
• Add npm run release script that runs commit-and-tag-version
• Update state/current-release.json as part of the release flow
• Update Hep's HEARTBEAT.md Step 5 to use npm run release instead of manual steps

Acceptance criteria

• npm run release bumps package.json version, updates CHANGELOG.md, creates git tag
• Version in cli.ts reads from package.json (fix for Supply Chain: Package hygiene for npm publishing #364 version mismatch)
• Dry-run mode works: npm run release -- --dry-run
• Hep's release checklist in HEARTBEAT.md reflects the new flow
• No CI regression

How to approach

⚠️ Use plan mode + brainstorming skill before writing any code.

1. Invoke brainstorming skill to explore: commit-and-tag-version vs semantic-release vs simple-release-action, .versionrc.json config options, how to sync version into cli.ts
2. Invoke writing-plans skill for a structured implementation plan
3. Implement via executing-plans skill after plan approval

Notes

• This partially overlaps with Supply Chain: Package hygiene for npm publishing #364 (version mismatch in cli.ts) — coordinate or close Supply Chain: Package hygiene for npm publishing #364 as part of this
• semantic-release is more powerful but heavier — evaluate in brainstorming whether it's overkill for now

[OneStepAt4time]

Self-resolved:
elease-please-config.json and .github/workflows/release-please.yml are already active in the repo. Automated changelog and GitHub releases are live as of v2.2.x. Closing as implemented.