write-trn-breaking-change

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name: write-trn-breaking-change description: Write a Breaking Change entry for a Livingdocs Technical Release Note (TRN) and insert it into the correct release file. Use this skill whenever a developer wants to document a breaking change, mentions "write breaking change", "add breaking change to release notes", or provides PR URLs and asks to document a breaking change for a specific release (e.g. "write the breaking change for release-2026-05"). This skill handles the full workflow: gathering PR details, writing the entry with Detect/Fix sub-sections, and inserting it into the release file.

Write TRN Breaking Change Entry

Breaking changes are the most upgrade-critical section of the TRN. Each entry must be detectable and fixable from its own text — an AI agent or operator should be able to walk through Breaking Changes and apply each fix without consulting other documentation.

This skill is the workflow. The entry's shape, tone, and rules live in .claude/trn-format-reference.md, which is the source of truth — read it before drafting and follow it rather than relying on memory.

Step 1: Gather inputs

Ask one question at a time — wait for each answer before asking the next:

1. Release — identifier in release-YYYY-MM format. Accept plain year/month and normalise it yourself.
2. GitHub PR URLs — ask whether they'd like to add all URLs at once or one at a time. If one at a time: ask for the first URL, then ask "Any more PRs? (say 'done' to continue)" and keep collecting until done. If all at once: accept a list of URLs in a single message.
3. Notification code(s) — the LivingdocsBreakingChange code(s) this change emits (e.g. LIBREAKING000). Collect all of them if there are several (e.g. one per affected property, like LIBREAKING000-propertyOne, LIBREAKING000-propertyTwo). Say "no" if the change emits no runtime warning (e.g. a static-only concern such as direct lib/ imports).
4. Notion requirement URL — original requirement page (if available). Say "no" to skip.
5. Additional context — free-form notes from the developer about the breaking change. Optional.

Step 2: Read the sources

• Fetch each GitHub PR: title, description, linked issues, code diff. Pay attention to:
  • Which config properties, API endpoints, or source-level imports are affected.
  • The old shape vs. the new shape (verbatim — Detect and Fix lines must use the exact property names from the code).
  • Whether the change is mechanical (e.g. property rename, key move) or judgment-based (e.g. semantic conflict where the user must choose).
• If a Notion URL was provided, fetch it to understand the original motivation.
• Check earlier releases for a matching deprecation. Most breaking changes that remove a property, API, or behaviour were first announced as a deprecation in an earlier release — typically around three releases earlier, though this is not guaranteed. Look under ## Deprecations :warning: in the earlier content/operations/releases/release-YYYY-MM.md files. If you find one, its prose, Detect, and Fix are a strong starting point — adapt them rather than writing from scratch. Still review it end to end: details may have changed between the deprecation announcement and the actual removal, and the deprecation entry may have surfaced edge cases worth carrying over.
• Read the existing ## Breaking Changes :fire: section in content/operations/releases/<release-identifier>.md to calibrate tone and to confirm the change isn't already documented.

Step 3: Write the breaking change entry

Write the entry following the Breaking Change entry shape and its Rules in .claude/trn-format-reference.md — the source of truth for the title, the **Code:** line, the concise prose intro with before/after, the greppable Detect, and the Fix. Read it now rather than restating it here.

Skill-specific note: if you adapted an earlier deprecation entry (Step 2), carry over its still-accurate detail and update whatever changed between the deprecation and the removal.

Step 4: Ask for feedback

Show the draft to the developer:

"Here's the draft. Does it look right? Anything to adjust — wording, missing edge cases, or the Detect/Fix specificity?"

Apply any requested changes. If the developer flags the entry as a deprecation rather than a breaking change, switch to the write-trn-deprecation skill instead.

Step 5: Insert into the release notes file

1. Open content/operations/releases/<release-identifier>.md.
2. Locate ## Breaking Changes :fire:.
3. Append the entry at the end of that section, before the next ## heading.
4. Save and confirm to the developer.

Step 6: Sanity-check after insertion

Verify the finished entry against the Rules in .claude/trn-format-reference.md (icon-free ### heading, **Code:** line with codes verbatim from the source, greppable Detect, both Detect and Fix present, no extra #### sub-headings). Then confirm the insertion itself: the entry sits inside ## Breaking Changes :fire:, before the next ## heading.

If any check fails, surface it to the developer and propose a fix before closing.