merge origin/main: regenerate component.mdx on the merged tree (os-regen step 3 hand-off)

The os-regen driver kept this branch's side of
content/docs/references/ui/component.mdx in merge commit 5f5b809 and
dropped main's object-grid keyboardNavigation row (1cbe165). Step 2
restored main's side; gen:schema and gen:docs on the merged tree (HEAD
the merge commit, no MERGE_HEAD) produce this page. Its delta against
origin/main 15fe567 is exactly this branch's one sortField row.

Claude-Session: https://claude.ai/code/session_01T9u38rswFp5Rw8DswRUReJ
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

content/docs/references/ui/component.mdx

@@ -735,7 +735,7 @@ Sort field and direction pair
 | **navigation** | `{ mode?: Enum<'page' \| 'drawer' \| 'modal' \| 'split' \| 'popover' \| 'new_window' \| 'none'>; preventNavigation?: boolean; openNewTab?: boolean; size?: Enum<'auto' \| 'sm' \| 'md' \| 'lg' \| 'xl' \| 'full'>; … }` | optional | Row-click navigation config — the same block `ListViewSchema.navigation` declares (`{ mode, size, openNewTab, preventNavigation }`) |
 | **editable** | `boolean` | optional | Enable inline cell editing |
 | **singleClickEdit** | `boolean` | optional | Enter cell edit on single click (default true when editable) |
-| **keyboardNavigation** | `boolean` | optional | [EXPERIMENTAL — not enforced] Arrow-key cell navigation on the WAI-ARIA grid pattern. Defaults to on when `editable` is set; a read-only grid keeps its Tab behaviour unless this is `true`. No renderer reads it yet: it is declared ahead of the grid's keyboard-navigation build, so authoring it changes nothing today |
+| **keyboardNavigation** | `boolean` | optional | Arrow-key cell navigation on the WAI-ARIA grid pattern: the grid's data cells become one Tab stop that the arrow keys, Home / End and Ctrl+Home / Ctrl+End move between. Defaults to on when the grid renders editable — `editable` set and the viewer allowed to edit; a grid that renders read-only keeps every cell its own Tab stop unless this is `true`, and `false` turns it off on an editable grid |
 | **resizable** | `boolean` | optional | Allow column resize (the renderer default is on) |
 | **resizableColumns** | `never` | optional | [REMOVED] `object-grid` property `resizableColumns` was removed in @objectstack/spec 17.7.0 (ADR-0049) — it was the legacy second spelling of `resizable`, read only when `resizable` was absent, so one switch had two spellings and a grid authoring both silently ignored this one. Use `resizable`. Rename the key; the value (a boolean) is unchanged. Run `os migrate meta --from 17` to list the mechanical edits for existing sources; apply them by hand. |
 | **reorderableColumns** | `boolean` | optional | Allow column drag-reorder |