quest: plan studio autosave, scene editing, broadcast sync, Wayland sources

quest/m2/capture-linux.md

@@ -22,9 +22,10 @@ unimplemented, because xdg-desktop-portal owns source selection:
 - **Display selection stays picker-driven.** On Wayland a bare `--display`
   goes to the portal and a non-X11 id is refused. Since #5089 a `Selection` replays
   its restore token across reopens within one process, but the token is never
-  exposed, so a new `moq` run always shows the picker. Either the token becomes
-  persistable (API plus CLI) so a previously-approved source is reused without
-  the picker, or this stays a documented limitation answered by the X11 path.
+  exposed, so a new `moq` run always shows the picker. Decided 2026-10-26
+  (maintainer): the token becomes persistable (API plus CLI), so a
+  previously-approved source is reused without the picker.
+  [Wayland studio sources](/quest/m3/studio/wayland-sources.md) consume it.
 - **System audio** needs a PipeWire monitor node.
   `moq_audio::capture::Source::System` exists but is macOS-only and returns
   `Unsupported` elsewhere. This is independent of the screencast portal.

quest/m3/studio/README.md

@@ -70,6 +70,10 @@ surface and zero-copy texture import, land before the cut.
 - [Zero-copy program encode](/quest/m1/studio-gpu/encode.md) - the program reaches the encoder as a GPU surface instead of a CPU readback
 - [Zero-copy source import](/quest/m1/studio-gpu/import.md) - captured and decoded frames reach the compositor as GPU textures instead of a CPU upload
 - [Studio on macOS and Windows](/quest/m3/studio/app.md) - the studio runs on macOS and Windows, not only Linux
+- [Autosave](/quest/m3/studio/autosave.md) - every edit is written to the scene file, with no save step or quit prompt
+- [Scene editing](/quest/m3/studio/scene-editing.md) - rename and reorder scenes, and resize the canvas while live through a new rendition
+- [Broadcast sources play in sync](/quest/m3/studio/broadcast-sync.md) - subscribed broadcasts and guests play audio and video on the publisher's timestamps, with `moq play`'s delay
+- [Wayland display and window sources](/quest/m3/studio/wayland-sources.md) - portal-picked sources that reopen without the picker
 - [Destinations](/quest/m3/studio/destinations.md) - RTMP, RTMPS, and WHIP push with per-destination codecs and shared encoders, on a UI-free egress library a hosted service can reuse
 - [Multiple canvases](/quest/m3/studio/multi-canvas.md) - landscape and portrait canvases composite at once from shared sources
 - [Guests](/quest/m3/studio/guests.md) - remote guests and phone cameras join through a moq-room link or QR code and appear as sources

quest/m3/studio/autosave.md

@@ -0,0 +1,18 @@
+# [S] Studio autosave
+
+## Goal
+
+`moq-studio` writes every change to the scene collection to its scene file
+shortly after it happens, with no save step and no prompt on quit. A crash
+loses at most the edits inside the debounce window. A failed write shows in the
+UI rather than being dropped.
+
+## Plan
+
+Decided 2026-10-26 (maintainer): autosave, not a dirty flag and a quit prompt.
+Debounce bursts such as dragging a slider, flush on quit, and write
+atomically (temporary file plus rename) so a crash never leaves a half-written
+file. The scene file stays diffable, so an autosave that changes nothing
+writes nothing. A scene path that does not exist yet is created by the first
+autosave, replacing the guide's "created on the first save" and
+**File > Save**. Update `doc/bin/studio.md`.

quest/m3/studio/broadcast-sync.md

@@ -0,0 +1,34 @@
+# [M] Broadcast sources play in sync
+
+## Goal
+
+A subscribed MoQ broadcast in `moq-studio`, guests included, plays its audio
+and video on the publisher's timestamps, so lip sync holds through network
+jitter and stalls. Today each track plays at its own live edge, so a stall
+can leave audio and video apart.
+
+## Plan
+
+Decided 2026-10-26 (maintainer):
+
+- **Scope:** broadcast sources only. Local devices keep the manual
+  per-source offsets in [Audio mixes](/quest/m3/studio/mixes.md).
+- **Delay:** reuse `moq play`'s timing, the `--delay auto` target from
+  moq-audio's jitter estimate (`rs/moq-audio/src/jitter.rs`,
+  `doc/concept/audio-jitter.md`), rather than a second algorithm or a manual
+  setting. As in `moq play`, the estimate is the broadcast's audio track's,
+  and video follows it rather than keeping its own, so one delay governs the
+  whole broadcast. A broadcast with no audio keeps video's own short delay.
+  Show each source's delay in the UI.
+
+Lift the shared part out of `moq play` into a library both binaries use,
+rather than copying it. The video side holds frames until their audio-aligned
+time, and a source still repeats its last frame rather than stalling the
+canvas. This replaces the live-edge behavior the studio app PR chose, where
+replaying a publisher's timestamp gaps pushed audio behind its own video. Here
+video waits for audio instead. Update `doc/bin/studio.md`.
+
+## Related
+
+- [Audio jitter target](/quest/m1/audio-jitter-target/README.md) - the delay estimate this reuses
+- [Guests](/quest/m3/studio/guests.md) - guests are broadcast sources and inherit this

quest/m3/studio/scene-editing.md

@@ -0,0 +1,22 @@
+# [M] Scene editing
+
+## Goal
+
+In `moq-studio`, scenes can be renamed and reordered, and the canvas can be
+resized while live, with no restart.
+
+## Plan
+
+Decided 2026-10-26 (maintainer): a resize while publishing adds a new video
+rendition under a new track name in a catalog update, and viewers switch to
+it. A track name never changes what it means (AGENTS.md), so the old track
+ends rather than changing resolution mid-stream. The compositor reallocates
+its canvas textures and the program encoder restarts on the new size.
+
+A rename updates every reference to the scene in the collection. Reordering
+is the order of the scene file's list. Update
+`doc/bin/studio.md`.
+
+## Related
+
+- [Multiple canvases](/quest/m3/studio/multi-canvas.md) - canvases of different sizes at once, sharing the resize path

quest/m3/studio/wayland-sources.md

@@ -0,0 +1,30 @@
+# [M] Wayland display and window sources
+
+## Goal
+
+On a Wayland desktop, `moq-studio` adds display and window sources through
+the xdg-desktop-portal picker. A source the user approved once reopens
+without the picker, across restarts of the studio. Today display and window
+sources capture only X11 and XWayland.
+
+## Plan
+
+Decided 2026-10-26 (maintainer):
+
+- **Token:** the portal restore token is persisted, which
+  [Linux capture parity](/quest/m2/capture-linux.md) makes possible in
+  moq-video. This quest consumes it.
+- **Storage:** the token lives in per-machine state (the XDG state directory,
+  keyed by scene collection and source), never in the scene file, so the scene
+  file stays portable and diffable. On another machine, or when the portal
+  rejects the token, the picker shows once and the new token is stored.
+- **Scene file:** the scene item records that the source is portal-picked, not
+  which monitor or window was picked, since only the portal knows that.
+
+Add the source kinds next to the X11 ones in moq-scene and the Sources panel,
+and update `doc/bin/studio.md`, which says display and window sources are
+X11-only.
+
+## Required
+
+- [Linux capture parity](/quest/m2/capture-linux.md) - the portal restore token becomes persistable