unioss-writing-planslisted

# Writing Plans ## Overview Write comprehensive implementation plans assuming the engineer has zero context for our codebase and questionable taste. Document everything they need to know: which files to touch for each task, code, testing, docs they might need to check, how to test it. Give them the whole plan as bite-sized tasks. DRY. YAGNI. TDD. Frequent commits. Assume they are a skilled developer, but know almost nothing about our toolset or problem domain. Assume they don't know good test design very well. **Announce at start:** "I'm using the unioss-writing-plans skill to create the implementation plan." **Context:** If working in an isolated worktree, it should have been created before execution time. **Save plans to:** `.walkthrough/<PREFIX>-[IID]/round-<N>/implementation.v1.md` (pipeline ticket mode) or `.walkthrough/plans/YYYY-MM-DD-<feature-name>.md` (standalone mode) - (User preferences for plan location override this default) ## Scope Check If the spec covers multiple independent subsystems, it should have been broken into sub-project specs during brainstorming. If it wasn't, suggest breaking this into separate plans — one per subsystem. Each plan should produce working, testable software on its own. ## File Structure Before defining tasks, map out which files will be created or modified and what each one is responsible for. This is where decomposition decisions get locked in. - Design units with clear boundaries and well-defined interfaces. Each file s