6409bdb062
The GameStream/Moonlight video plane is a separate encode loop that lacked the
session-following the native punktfunk/1 plane has, so a mid-stream Desktop<->Game
switch killed the stream ("video stream failed") instead of following it.
* Normalize the session env like the native plane: extract open_gs_virtual_source,
which detects the LIVE compositor + apply_session_env/apply_input_env (gamescope
ATTACH default -> resize-on-attach to the box's own game-mode session at the
client mode; KWin/Mutter retargeting). GameStream previously ran a bare detect()
against raw process env, so in game mode it bare-spawned a COMPETING gamescope
instead of attaching to the box's session.
* In-place capture-loss rebuild: replace the `?` that ended the stream with a
bounded rebuild (re-detect the live compositor via the same factory, build the
new source BEFORE dropping the old, reopen the encoder, force an IDR) — keeping
the send thread + packetizer + socket + RTP clock. A same-resolution
Desktop<->Game toggle is now FOLLOWED with no Moonlight reconnect.
Protocol limit (unchanged): a mid-stream RESOLUTION change is impossible on
GameStream (WxH locked at ANNOUNCE; no Reconfigure) — a session toggle keeps the
negotiated mode, so this isn't hit. The portal/synthetic source passes no rebuild
closure (propagates as before).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>