READY light: pods report load-complete to the operator roster

The roster showed "registered" for a still-loading pod and a ready one
alike -- with multi-minute contended loads the operator couldn't tell
who they'd be waiting on.  When the app ladder reaches WaitingForLaunch
the pod sends one empty route -10 frame on its live relay game socket
(BTRelayNotifyReady; socket mirrored at HELLO); the relay announces
SEAT n READY (k/m loaded) and the console GUI lights the seat
bright-green with a "N pod(s) LOADED+READY" banner.

Verified LIVE by the operator: blue (seated) -> teal (registered) ->
green (ready) in order, twice.  Also resolved the load-speed mystery:
loads are ~30s uncontended; the 1-2+ minute cases were assistant
background test runs competing with the user's interactive sessions on
the same machine (memory note added -- no game-spawning tests while the
user is testing).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

engine/MUNGA/APP.cpp

@@ -1416,6 +1416,11 @@ void
 				Tell("Sent ready message to ourselves\n");
 			}
 
+			{
+				// tell the operator this pod finished loading (READY light)
+				extern void BTRelayNotifyReady(void);
+				BTRelayNotifyReady();
+			}
 			{
 				// relay launches that arrived MID-LOAD fire now (they could
 				// not enter the queue then -- see L4APP.cpp pend counter)