feat(transcription): add download transcript as txt button

[2f488f42]

transcription-tool/frontend/src/App.tsx

@@ -332,6 +332,21 @@ export default function App() {
                     >
                         <Copy className="h-5 w-5" />
                     </button>
+                    <button
+                        onClick={() => {
+                            const transcriptText = flatMessages.map(m => `[${m.display_time}] ${m.speaker}: ${m.text}`).join('\n');
+                            const filename = `${detailMeeting.title}.txt`;
+                            const blob = new Blob([transcriptText], { type: 'text/plain;charset=utf-8' });
+                            const link = document.createElement('a');
+                            link.href = URL.createObjectURL(blob);
+                            link.download = filename;
+                            link.click();
+                            URL.revokeObjectURL(link.href);
+                        }}
+                        className="text-slate-500 hover:bg-slate-100 dark:hover:bg-slate-800 p-2 rounded" title="Download Full Transcript as TXT"
+                    >
+                        <FileText className="h-5 w-5" />
+                    </button>
                     <button onClick={(e) => handleDeleteMeeting(e, detailMeeting.id)} className="text-red-500 hover:bg-red-50 dark:hover:bg-red-900/20 p-2 rounded"><Trash2 className="h-5 w-5" /></button>
                 </div>
               </header>