player connect-disconnect

WEBSOCKET_NETWORKING.md

@@ -5,11 +5,12 @@
 The Windows WebSocket transport uses Boost.Asio and Boost.Beast to run a
 server-sequenced deterministic lockstep simulation. A client receives one
 authoritative state at a completed tick boundary. After that, the server sends
-only numbered tick messages containing ordered player commands (or an empty
-command list).
+	only numbered tick messages containing ordered destination and presence
+	commands (or an empty command list).
 
-The current command surface is intentionally limited to
-`SetCharacterDestinationCommand`.
+Client intent is intentionally limited to `SetCharacterDestinationCommand`.
+The server also sends `SetCharacterEnabledCommand` in tick bundles when a
+configured player slot connects or disconnects.
 
 ## Runtime Architecture
 
@@ -21,6 +22,9 @@ The current command surface is intentionally limited to
 - Each accepted connection is assigned the first free character ID from the
   campaign's `networkPlayerSlots`; the connection is rejected when all slots
   are occupied.
+- Player slots start disabled. The server consumes and broadcasts an enabled
+  command on the next tick for each connection and disconnection, including to
+  the newly connected client.
 - The initial message contains the state, completed snapshot tick, assigned
   player ID, tick duration, two-tick input delay, and compatibility fingerprint.
 - Destination inputs cross from the Asio thread through a queue. The simulation
@@ -102,8 +106,8 @@ Message types are:
 - `initial_state` (server to client): one state snapshot and lockstep metadata;
 - `destination_input` (client to server): monotonic client sequence and a
   centimetre-normalized finite target;
-- `tick` (server to client): tick ID, globally sequenced commands, and
-  post-tick diagnostic state hash;
+- `tick` (server to client): tick ID, globally sequenced destination and
+  character-presence commands, and post-tick diagnostic state hash;
 - `error` (server to client): invalid input, incompatibility, or full server.
 
 Protocol v1 is not compatible. Malformed payloads, non-finite or out-of-range
@@ -161,7 +165,8 @@ Launch the Windows game and select `battle_zone_multiplayer`. The client connect
 
 CTest covers protocol-v2 round trips and validation, input-delay ordering,
 fixed-tick replica behavior, campaign slot metadata, initial connection and
-slot assignment, destination submission, and contiguous tick consumption.
+slot assignment, connection/disconnection presence propagation, destination
+submission, and contiguous tick consumption.
 
 ## Current Limitations