docs: clarify section authoring and Archify trust boundaries

docs/core/maintain.md

@@ -19,7 +19,16 @@ Open the development server address printed in the terminal. The site uses the `
 
 ## Add or change a page
 
-Edit Markdown in `docs/`. Include `title` and `description` frontmatter and add the page ID to `sidebars.ts`. Keep the documentation’s future scope open until it is agreed.
+Include `title` and `description` frontmatter. Place each page in its owning section and add its document ID to that section’s sidebar:
+
+| Section | Content directory | Sidebar configuration |
+| --- | --- | --- |
+| Organization | `docs/organization/` | `sidebars/organization.ts` |
+| Strategy | `docs/strategy/` | `sidebars/strategy.ts` |
+| Contribution | `docs/contribution/` | `sidebars/contribution.ts` |
+| Portal maintenance and reference | `docs/core/` | `sidebars.ts` |
+
+Keep these content roots disjoint. Preserve existing URLs when moving pages. Specific AI initiatives and organizational reporting lines remain subject to agreement.
 
 ## Validate the change