20260901T1730Z changelog convention

What. Change-log convention introduced: one file per entry under changelog/YYYY-MM/, frontmatter (actor, category, refs) plus What/Why/Verify body, entry committed with the change it describes. Wired into CLAUDE.md (rule) and the writing-docs skill (new doc layer). The skill's stale claim that the decisions log lives in the PRD corrected to docs/decisions.md.

Why. Multiple agents work this project in parallel; per-change entries with reasoning and refs make their work queryable and reviewable. Fragment-per-file (towncrier-style, keshi's .changelogs/unreleased/ precedent) avoids merge conflicts; git keeps review free via the same-commit rule. Decided with Agus, 2026-09-01.

Verify. changelog/README.md; the CLAUDE.md Rules section; the writing-docs layers table.