- Implemented.

Safari/iPhone recording now uses MP4/AAC when WebM is unavailable.
WebM remains the default when supported and FFmpeg is disabled.
Added optional FFmpeg profiles: recommended M4A/AAC-LC or requested 
MP4/H.264 + AAC.
Added MIME-aware, playsinline audio playback.
Added dashboard controls under Plans & Platform → Voice Transcoding / 
FFmpeg.
Added Apache/Nginx media MIME configuration and documentation.
Core implementation: voice_transcoder.php (line 72), messages.php (line 
86), and cyberchat-app.js (line 635).

nginx-example.conf

@@ -39,6 +39,26 @@ server {
         return 404;
     }
 
+    location ~* ^/uploads/voice/.*\.m4a$ {
+        default_type audio/mp4;
+        try_files $uri =404;
+    }
+
+    location ~* ^/uploads/voice/.*\.aac$ {
+        default_type audio/aac;
+        try_files $uri =404;
+    }
+
+    location ~* ^/uploads/voice/.*\.webm$ {
+        default_type audio/webm;
+        try_files $uri =404;
+    }
+
+    location ~* ^/uploads/voice/.*\.mp4$ {
+        default_type video/mp4;
+        try_files $uri =404;
+    }
+
     # PHP files
     location ~ \.php$ {
         fastcgi_pass unix:/run/php/php8.1-fpm.sock; # adjust PHP version