Sync the self-hosting stack

CHANGELOG.md

@@ -9,6 +9,34 @@ one of them changed. An entry says which artefact and which version, so `web 0.1
 Every version published to a channel appears here. Nothing is written from memory afterwards: a build
 cannot be published without its entry.
 
+## 2026-10-08 — Hear the remote machine from the remote-desktop viewer `agent 0.47.0` `api 0.129.0` `web 0.159.0`
+
+The remote-desktop toolbar has a new speaker button. It turns on the sound of the machine you are
+watching, so you can hear a video play, a notification, or a call, and turns it off again. It works
+with JPEG images as well as with H.264 and H.265 video.
+
+**It is off when a session opens, and off means off.** Nothing is listened to on the machine until you
+press the button, and pressing it again stops the listening on the machine, not only the playing in
+your browser. What you hear is what the machine plays through its speakers; its microphone is never
+opened. The sound is sent only while the notice is standing on the person's screen, and nothing is
+recorded or kept. The person at the machine is not told that someone is listening: the notice names who
+is viewing and controlling, and does not yet mention sound. Only the agent's log records that the
+sound was turned on and off.
+
+The machine encodes the sound as AAC at 128 kbit/s with the encoder Windows already carries, and a
+machine that is playing nothing sends nothing. The sound and the picture are not synchronised: expect
+them to differ by a tenth of a second or two, which is fine for hearing a notification or a call and
+not good enough to judge lip-sync.
+
+The button appears when your browser can play AAC (Chrome, Edge and Safari can; Firefox depends on its
+platform codecs) and the machine's agent is updated. When the machine cannot oblige, the button turns
+into a muted speaker and the status bar says why: no sound output (most virtual machines and servers
+have none), no AAC encoder (on Windows Server, the Media Foundation feature is not installed), or the
+sound stopped.
+
+Update the API, the web image and the agent release image. No database update is required. With an
+older agent or an older API the button is not shown and nothing changes.
+
 ## 2026-10-08 — A toolbar of icons, and a third way to size the remote screen `web 0.158.0`
 
 Every action on the remote-desktop toolbar is now an icon with its name on hover: Ctrl+Alt+Del, the