fix(iso): set bash as default shell for bee user

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/config/hooks/normal/9000-bee-setup.hook.chroot

@@ -7,9 +7,9 @@ echo "=== bee chroot setup ==="
 
 ensure_bee_console_user() {
     if id bee >/dev/null 2>&1; then
-        usermod -d /home/bee -s /bin/sh bee 2>/dev/null || true
+        usermod -d /home/bee -s /bin/bash bee 2>/dev/null || true
     else
-        useradd -d /home/bee -m -s /bin/sh -U bee
+        useradd -d /home/bee -m -s /bin/bash -U bee
     fi
 
     mkdir -p /home/bee