docs(13-08): defer AIUI-over-host background regression on mobile/companion

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.planning/phases/13-aiui-functional-conversational-node-control-and-content-surf/deferred-items.md

@@ -41,3 +41,16 @@ Out-of-scope discoveries found while executing this phase. Logged, not fixed.
 - Logged to `.planning/WINDOWS.md` id 19 (kind: `unrun-verify`) so it blocks `/gsd-ship` until
   someone with ownership of `prod_orchestrator.rs` lands the one-line fix and a full
   `cargo test --package archipelago assistant::` run actually exercises 13-05's tests.
+
+## Deferred from 13-08 UAT (2026-08-05): AIUI draws its own background over the host default on mobile + companion
+
+- Operator report during Task 3 verification: the embedded AIUI paints an opaque background of
+  its own on top of the host's default background on **mobile** and the **companion app**;
+  desktop was fine at last check. Regression window: the AIUI bundle deployed 2026-08-05
+  (first build from the in-repo aiui/ after the delegation wiring) vs. the pre-phase-13 bundle.
+- Likely area: embedded-mode theming — App.vue's mount-time `isEmbeddedFlag` dark-mode forcing
+  and whatever body/root background AIUI sets when `?embedded=true`; the embed contract wants
+  the host chrome's background to show through (transparent), not AIUI's own.
+- Why deferred: cosmetic, does not block 13-08's confirm-gate checkpoint; needs on-device
+  mobile + companion reproduction to fix honestly (feedback_test_before_claiming_fixed).
+- Suggested owner: fold into 13-10/13-11 (wave 4 AIUI work) or a verify-work gap plan.