GroupChatInfoView: move chat-ttl footer caption out of SectionView lambda

Same pre-card-chrome pattern as ChatInfoView (fixed in b1a1dad8):
SectionTextFooter("Delete chat messages from your device.") sat inside
the SectionView around ChatTTLOption, so it rendered inside the white
card after PR #6777 added card chrome. Move it out so the caption sits
below the card iOS-style.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/group/GroupChatInfoView.kt

@@ -697,8 +697,8 @@ fun ModalData.GroupChatInfoLayout(
           }
         }
         ChatTTLOption(chatItemTTL, setChatItemTTL, deletingItems)
-        SectionTextFooter(stringResource(MR.strings.chat_ttl_options_footer))
       }
+      SectionTextFooter(stringResource(MR.strings.chat_ttl_options_footer))
       SectionDividerSpaced(maxTopPadding = true, maxBottomPadding = true)
 
       if (!groupInfo.nextConnectPrepared && !groupInfo.useRelays) {