diff --git a/.env.example b/.env.example
index 01f8079..c4be0aa 100644
--- a/.env.example
+++ b/.env.example
@@ -62,11 +62,16 @@ CORS_ALLOWED_ORIGINS=
 # neither Origin nor Referer (curl, server-to-server callers) are
 # always allowed.
 #
-# Default is empty: CSRF check disabled (operator opt-out). For a
-# browser-exposed deployment this should be set to the SvelteKit
-# origin, e.g. https://app.example.com. For a same-origin
-# docker-compose deploy where only one origin exists, set the same
-# value the browser uses.
+# Empty does NOT mean "off" for browsers: cookie-authenticated admin
+# mutations FAIL CLOSED (403) when this is empty, since there's no
+# allowlist to check the Origin against. Non-cookie callers (curl,
+# bots with a Bearer token, no Origin/Referer) are still allowed.
+# So set this to the SvelteKit origin for any browser-exposed deploy,
+# e.g. https://app.example.com. For a same-origin docker-compose deploy
+# set the same value the browser uses.
+#   Local dev (native `npm run dev`): the Vite origin is
+#   http://localhost:5173 — set ADMIN_ALLOWED_ORIGINS=http://localhost:5173
+#   or admin toggles (e.g. enabling the analysis worker) return 403.
 ADMIN_ALLOWED_ORIGINS=
 
 # ----- Admin bootstrap -----