docs(skills): the objectstack-ui navigation rule states the derived record surface per flow

The Surface bullet in skills/objectstack-ui/rules/navigation.md said a
field-heavy object opens create/edit/detail as a full page and that mobile
always pages. deriveRecordFlowSurface routes only the view flow to a page;
the create, edit and child task flows open a modal, bounded on desktop and
full-screen on mobile; a light record on desktop opens every flow in a
drawer. The bullet now states that mapping, drops the "(or object)"
placement (navigation is not an object key) and pays its tokens inside the
file: net 0 lines, 2273 tokens against ceiling 2273. An @objectstack/skills
patch changeset accompanies it.

Claude-Session: https://claude.ai/code/session_01VqGhCg9wdsBXPz54uAEWg7
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

.changeset/23753-navigation-record-surface.md

@@ -0,0 +1,9 @@
+---
+'@objectstack/skills': patch
+---
+
+docs(skills): the `objectstack-ui` navigation rule states the derived record surface per flow — viewing routes to a page, creating or editing opens a modal bounded on desktop and full-screen on mobile, a light record uses a drawer (#23753)
+
+Clause-②: no
+
+`skills/objectstack-ui/rules/navigation.md`'s Surface bullet said a field-heavy object opens create/edit/detail as a full page and that mobile always pages. The platform's derivation (`deriveRecordFlowSurface` in `@objectstack/spec`) routes only the `view` flow to a page; the create, edit and child task flows never route — a field-heavy record, or any record on mobile, opens them in a modal that is bounded on desktop and full-screen on mobile, and a light record on desktop opens every flow in a drawer. The bullet now states that mapping and names the override only where the spec declares it: `navigation.mode` on the list view (`navigation` is not an object key). Text only; nothing an author writes changes.

skills/objectstack-ui/rules/navigation.md

@@ -128,10 +128,10 @@ at runtime from how heavy the record is + the client viewport, because an author
 (especially an AI) cannot know the client's screen. **Write the data (fields,
 `fieldGroups`); let the platform lay it out.**
 
-- **Surface (page vs drawer).** Derived from field count: a field-heavy object
-  opens create/edit/detail as a **full page**; a light one as a **drawer**. Mobile
-  always pages. Don't set it. To force it for a specific object, set
-  `navigation.mode` (`page` | `drawer` | `modal`) on the list view (or object) — or,
+- **Surface.** Derived from field count and viewport. A field-heavy record, or
+  any on mobile, is viewed on a **page** and created/edited in a **modal**
+  (bounded on desktop, full-screen on mobile); otherwise a **drawer**. To force
+  it, set `navigation.mode` (`page` | `drawer` | `modal`) on the list view — or,
   for bespoke layout, assign a record `Page`.
 - **Field width.** **Omit it** (`auto` sizes by widget type × current columns —
   textarea / rich-text / file take the row). Both keys are valid: `colSpan`