docs(references): regenerate data/feed with the conditional property-reference rung

gen:docs output only: data/feed renders two enums and no Properties
table, so its title drops to the next rung. No other page moves.

Claude-Session: https://claude.ai/code/session_01ARcDurZ5j34RdqsGgc4jgH
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

content/docs/references/data/feed.mdx

@@ -1,5 +1,5 @@
 ---
-title: Feed schema — Data Protocol property reference
+title: Feed schema — Data Protocol reference
 navTitle: Feed
 description: "Activity-timeline UI config enums, and the sys_activity.type built-in set."
 ---