docs: RetroArch frontend launch race, claim-based online status and TZ

docs/ecosystem/retroarch-cloud-sync.md

@@ -104,6 +104,22 @@ environment:
 
 Whenever a folder can't be matched, the serial to add is logged.
 
+## Known RetroArch issues
+
+These happen inside RetroArch, before any request reaches RomM.
+
+### Launching a game from a frontend
+
+RetroArch syncs when it starts. When a frontend such as muOS starts RetroArch with a game already chosen, the core can load the local save before that sync finishes. The game then runs on the old local save instead of the one just downloaded, and the next sync uploads that old save as the newest version. Other frontends that start RetroArch with a game (ES-DE, Batocera, Android launchers) are likely affected in the same way.
+
+To avoid it, open RetroArch on its own first and let the sync finish, then launch the game.
+
+If a stale or blank save was already uploaded, the good one is still in the game's `autosave` [version history](../using/saves-and-states.md#save-slots). Delete the bad newest version in RomM, and RetroArch downloads the previous one on its next sync.
+
+### `Begin failed` after closing content
+
+RetroArch sometimes logs `Begin failed` with HTTP status `-1` when it syncs after **Close Content**. The request never reaches RomM, so nothing shows up in RomM's logs. Restart RetroArch and it syncs normally.
+
 ## Browsing with other WebDAV clients
 
 The same path works read-only in generic WebDAV clients, such as a file manager that mounts WebDAV shares:

docs/using/devices.md

@@ -29,7 +29,7 @@ An account without the `devices.write` permission can't register devices, so its
 
 A game you send to one of your devices is added to its download queue and fetched the next time the device is online.
 
-Only devices whose app reports that it accepts installs are offered, which leaves out browsers and RetroArch. Devices also show their online status, meaning the app holds an open connection to the `/devices` socket, as a supporting app does while it runs.
+Only devices whose app reports that it accepts installs are offered, which leaves out browsers and RetroArch. Devices also show their online status: a device is online while its app holds an open connection to the `/devices` socket, or when it checked for installs in the last 90 seconds. An app that only checks every few minutes shows as offline between checks, but still picks up the request.
 
 A request waits in the device's queue until the device takes it and reports back. You get a [notification](notifications.md) when it finishes or fails, and you can cancel a request any time before it finishes. A request nothing picks up expires after `DEVICE_INSTALL_REQUEST_TTL_DAYS` days without a change (2 by default).
 

docs/using/saves-and-states.md

@@ -78,6 +78,8 @@ A save or state can be renamed, and its screenshot follows it. The new name has
 
 Saves and states written in the browser are named after the game and the local time they were captured, so the timestamp in the name matches your clock.
 
+A new version of a save uploaded by a device or RetroArch is tagged with the server's time instead. That follows the container's time zone, which is UTC unless you set `TZ` (for example `TZ=America/New_York`) in RomM's environment.
+
 When you share a save or state with other users, they see its author but not its favorite flag or labels, which stay yours.
 
 ## Format/core compatibility