docs(agents): record the dashboard sections rendering exception

renderDashboardCollections/renderSectionHTML re-render dashboard
sections from /api/dashboard/sections JSON on library switch, settings
save, and refresh — deliberately kept in TypeScript to preserve the
switch fade on the app's most interactive page. First-paint section
markup remains templ (Dashboard handler in internal/router/frontend.go).

Recorded in the Rendering ownership section as a sanctioned exception
so it is not silently 'fixed' without restoring a templ-partial fade
path, and so the pattern is not cloned to new pages. (User-directed:
the dashboard keeps its fade; every other page stays templ-rendered.)

AGENTS.md

@@ -32,6 +32,15 @@ stats, toasts, password validation. Anything else that renders app UI
 in TypeScript is a defect; if a templ twin of it exists, one of the two
 must be deleted.
 
+**Documented exception — dashboard sections**: `renderDashboardCollections`
+/ `renderSectionHTML` in `web/src/dashboard.ts` re-render dashboard
+sections from `/api/dashboard/sections` JSON (library switch, settings
+save, refresh button) to preserve the switch fade/transition on a page
+with heavy interactivity. First-paint section markup is still templ
+(Dashboard handler in `internal/router/frontend.go`). This exception is
+deliberate; do not clone it to new pages, and do not "fix" the dashboard
+without restoring a templ-partial fade path first.
+
 ## Library visibility (family-lens rule) — ALWAYS apply
 
 Per-user library visibility (`library_visibility` table, default-ALLOW: