Add documentation for the current code/feature. Follow .cursor/rules/base/docs.mdc and .cursor/rules/base/readme.mdc.

Where to write

Layer	Role	Update when
`apps/docu/content/docs/` MDX	Architecture, ADRs, how-to	Behavior, architecture, commands, conventions, or workflow changed
`.cursor/rules`	Short constraints	A convention the agent must not violate changed
Nearest README	How to run this app/package; links only	Scripts, setup, or package purpose changed

Inline comments only when the code is otherwise misleading. Do not copy MDX into rules or READMEs. Do not @-attach MDX.

Identify the topic: Matching docs section, then existing topic page (create a page only if none fits)
Write or patch MDX if the canonical explanation changed
Patch README only for run/setup/scripts; link the MDX
Patch the glob-matched .mdc only if a constraint changed

add-documentation