feat(studio): reload or ask on an outside edit to the scene file

README.md

@@ -304,9 +304,17 @@ leaving half of it, and a collection that has not changed is not rewritten, so
 a hand-written file keeps its comments and layout until the next edit in the
 studio. A failed write shows in the status bar and
 is retried every second; until one succeeds, a crash loses every edit since the
-last write. To edit the file by hand while the studio runs, save it and pick
-**File > Reload**; an edit in the studio before that overwrites it. A new
-canvas size or frame rate takes a restart.
+last write. A new canvas size or frame rate takes a restart.
+
+The file can be edited by hand, or by another studio, while the studio runs.
+The studio looks at it every second and before each write. With no edits of
+its own unsaved, it reloads the change, as **File > Reload** does, which
+replaces even unsaved edits. If both sides changed, or the change cannot be
+loaded, the studio saves nothing until you pick **Keep the studio's**, which
+writes its version over the file, or **Take the file's**; quitting before you
+pick saves nothing. A file deleted while the studio runs is written again. One
+overwrite remains possible: a change saved in the instant between the studio's
+last look and its write replacing the file.
 
 The last 100 edits are written the same way beside the scene file, as
 `show.history.toml` for `show.toml`, after the scene file, and opening the

quest/m0/README.md

@@ -83,7 +83,6 @@ repository.
 - [Studio on Windows](/quest/m0/app-windows.md) - the studio runs on Windows, not only Linux
 - [Viewer-side composition](/quest/m0/compose/README.md) - sources as their own tracks plus a layout track, composed by viewers, with a server-composed program as the fallback
 - [The program encoder drains](/quest/m0/program-drain.md) - a hardware encoder never loses the program's last frames at exit or on pause
-- [Outside edits to the scene file](/quest/m0/outside-edits.md) - autosave reloads or asks instead of overwriting a change made outside the studio
 - [Scene editing](/quest/m0/scene-editing.md) - rename and reorder scenes, and resize the canvas while live through a new rendition
 - [Broadcast sources play in sync](/quest/m0/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/m0/wayland-sources.md) - portal-picked sources that reopen without the picker