From 7578d48d3dcf75fc6a36b6486781d4c8ccec16a3 Mon Sep 17 00:00:00 2001
From: Lucas Berger <me@lucasberger.ca>
Date: Thu, 18 Jun 2026 13:56:32 -0400
Subject: [PATCH] fix(17): IN-01 pull focus back into dialog when activeElement
 escapes

---
 apps/pwa/src/hooks/useFocusTrap.ts | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/apps/pwa/src/hooks/useFocusTrap.ts b/apps/pwa/src/hooks/useFocusTrap.ts
index 12fb791..e55c725 100644
--- a/apps/pwa/src/hooks/useFocusTrap.ts
+++ b/apps/pwa/src/hooks/useFocusTrap.ts
@@ -43,6 +43,16 @@ export function useFocusTrap(
     const first = focusable[0];
     const last = focusable[focusable.length - 1];
 
+    // Containment guard (IN-01): if focus has somehow landed outside the dialog
+    // (programmatic focus, browser quirk), neither boundary condition below
+    // matches and Tab would walk background content. Pull focus back to the
+    // first focusable instead of relying on a boundary-only trap.
+    if (!dialogRef.current.contains(document.activeElement)) {
+      e.preventDefault();
+      first.focus();
+      return;
+    }
+
     if (e.shiftKey) {
       // Shift+Tab: if on first element, wrap to last
       if (document.activeElement === first) {