devex: changelog system

[IMB11]

We really suck at changelogs - we should be documenting everything we do - this will encourage it.

How it works

1. PR is opened

A GitHub Actions workflow (changelog-comment.yml) posts a comment with a Keep a Changelog template. Each product area (App, Website, Hosting) gets its own collapsible <details> section, so a single PR can document different changes for different products.

If the PR targets another PR's branch (child PR), the bot adds an admonition linking to the parent PR.

2. Author fills in the comment

The author edits the bot comment, expanding the relevant product sections and writing bullet points under the standard headings (Added, Changed, Deprecated, Removed, Fixed, Security). Empty sections and products are ignored.

3. Collecting changelogs

Before deploying main → prod, run:

pnpm changelog:collect
# If app entries exist:
pnpm changelog:collect -- --version X.Y.Z
# Preview without writing:
pnpm changelog:collect -- --dry-run

The script:

• Finds all PRs merged into main since the last prod commit
• Parses each PR's bot comment using keep-a-changelog
• Auto-links #issue references to GitHub
• Groups entries by product and inserts into packages/blog/changelog.ts - can edit before committing to main to polish/QA
• Marks processed comments with a "baked" admonition

Uses GITHUB_TOKEN env var, or falls back to gh auth token.

[modrinth-bot]

Frontend previews

Last deployed commit is 1c2f9a1be44c40f05ae9a7770391c05268375c49

Environment	URL
staging	https://git-1c2f9a1b-frontend-staging.modrinth.workers.dev
production	https://git-1c2f9a1b-frontend.modrinth.workers.dev

[tdgao]

LGTM!