feat(admin): preview response media

Show who-likely choices in human terms and provide protected photo and audio previews in activity and user response views. Fetch media by response ID through an authenticated Edge Function that enforces the view_responses permission.

apps/admin/src/pages/activity/UserActivityPage.tsx

@@ -524,8 +524,11 @@ export function UserActivityPage() {
                                             <TableCell>
                                                 <ResponseAnswer
                                                     answer={item.answer}
+                                                    responseId={item.id}
                                                     questionType={item.question?.question_type}
                                                     responseData={item.response_data}
+                                                    responderId={item.user_id}
+                                                    responderName={item.profile?.name || item.profile?.email}
                                                 />
                                             </TableCell>
                                             <TableCell className="text-muted-foreground text-sm whitespace-nowrap">