A netplay match that ends early returns both players to the lobby. The
runtime knew why (netplay_soft_exit's origin) but only printed it to
stdout, so players saw the lobby again with no reason. A boot-digest
mismatch (peers booted different BIOS images or boot settings) first
held a black window for the full 20 s admit-stall watchdog.
netplay_soft_exit now records a sentence for its origin, and the soft
return to the lobby puts it on the launcher's status line through
last_error (the room and browser views already show it). The dig0 gate
timestamps a mismatch; once the same pair of digests has held for 3 s,
the watchdog ends the match with its own reason. A peer that gets the
other side's BYE while it sees the same mismatch reports the mismatch,
not "the other player left". A CLI match prints the sentence to stderr.
The origin-to-text map and the grace decision live in
netplay_exit_reason.c, covered by netplay_exit_reason_test. Builds on
the previous commit's psx_lobby_set_last_error.
Alexandros Mandravillis
5c7a37146c