v0.7.0 — four game types, a lobby you can read and leave, and a multiplayer game that makes a sound

The multiplayer set-up, the lobby, the start of a game, and four signals a remote client had never
been sent. Reasoning, the preset table and what was verified how: CHANGELOG.md.

- Co-op, Competitive, Cutthroat, Solitaire and Custom, on both screens, from one shared block —
  they had drifted, and each was missing a question the other asked.
- A player reads the whole rule set before taking a seat, may leave a lobby or a running game, and
  keeps a seat across a reload. The host may clear a chair. The browser remembers every game it is
  in, not just the last one.
- The start of a game is drawn: a handoff beat, an announcement, the code and type in the header.
- Sound, the timetable flash, announcements and the just-drawn badge now reach a remote client;
  justDrawn goes to the seat that drew it and nobody else.
- Played on StartOS, which found the rest: an Extra belongs to the player who played it, the board
  never named the Superintendent, bot seats were reported as absent players, and rule section
  numbers are out of every string a player reads.

Also carries the previous session's Heavy Grade documentation work — asked again, answer unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016JczK5i33ZNSf2PtzZqdhS

src/server/lobby.ts

@@ -50,7 +50,12 @@ export type Lobby = {
 };
 
 export type CreateResult = { lobby: Lobby; session: PlayerSession };
-export type JoinResult = { ok: true; lobby: Lobby; session: PlayerSession } | { ok: false; code: 'LOBBY_FULL' | 'ALREADY_STARTED' };
+export type JoinResult =
+  | { ok: true; lobby: Lobby; session: PlayerSession }
+  | { ok: false; code: 'LOBBY_FULL' | 'ALREADY_STARTED' | 'NAME_TAKEN' };
+/** `empty` when the last human has gone — the caller drops the lobby rather than leaving a table of
+ * bots waiting for a host who no longer exists. */
+export type LeaveResult = { lobby: Lobby; empty: boolean };
 export type StartResult = { ok: true; playerNames: string[]; botSeats: PlayerIndex[] } | { ok: false; code: 'NOT_HOST' | 'BAD_PLAYER_COUNT' };
 
 /**
@@ -140,6 +145,19 @@ export function joinLobby(lobby: Lobby, displayName: string): JoinResult {
   const seatIndex = lobby.seats.findIndex((s) => s === null);
   if (seatIndex < 0) return { ok: false, code: 'LOBBY_FULL' };
 
+  /**
+   * TWO PLAYERS CANNOT SHARE A NAME (2026-08-23).
+   *
+   * The name is not decoration: it labels the district on the Division map, it is what the turn
+   * chart means by "waiting on Jesse", and `record()` puts it in front of every line that player
+   * causes. Two identical names make all three ambiguous, and there is no way to fix it once the
+   * game starts — the names are locked into the session at `Lobby.Start`. Refused rather than
+   * silently suffixed: a player should play under the name they chose, or be told to choose again.
+   */
+  const wanted = displayName.trim().toLowerCase();
+  const clash = lobby.seats.some((s) => s?.kind === 'human' && s.displayName.trim().toLowerCase() === wanted);
+  if (clash) return { ok: false, code: 'NAME_TAKEN' };
+
   const token = randomUUID();
   const session: PlayerSession = { token, gameId: lobby.gameId, player: seatIndex, displayName };
   const seats = [...lobby.seats];
@@ -151,6 +169,35 @@ export function joinLobby(lobby: Lobby, displayName: string): JoinResult {
   };
 }
 
+/**
+ * GIVING UP A SEAT — a player leaving, or the host clearing somebody out of a chair.
+ *
+ * There was no way out of a lobby at all before 2026-08-23: a mis-join or a player who wandered off
+ * wedged the table, because Start needs every chair filled and `setBotSeat` refuses to touch an
+ * occupied human seat. One function serves both, since they differ only in whose seat is named, and
+ * `http.ts` is what checks that a caller naming somebody else's seat is the host.
+ *
+ * Host rights move exactly as they do on a dropped connection (`reassignHost`), and the caller is
+ * told when the last human has gone so the lobby can be dropped rather than left orphaned.
+ */
+export function leaveLobby(lobby: Lobby, token: string, seat?: PlayerIndex): LeaveResult {
+  const index =
+    seat === undefined ? lobby.seats.findIndex((s) => s?.kind === 'human' && s.token === token) : seat;
+  const occupant = index >= 0 ? (lobby.seats[index] ?? null) : null;
+  if (index < 0 || occupant?.kind !== 'human') return { lobby, empty: false };
+
+  const seats = [...lobby.seats];
+  seats[index] = null;
+  const departing = occupant.token;
+  const withoutThem: Lobby = {
+    ...lobby,
+    seats,
+    joinOrder: lobby.joinOrder.filter((t) => t !== departing),
+  };
+  const empty = !seats.some((s) => s?.kind === 'human');
+  return { lobby: reassignHost(withoutThem, departing), empty };
+}
+
 /** Host-only in effect (`http.ts` checks the caller's token against `hostToken` before calling
  * this) — marks an empty seat as bot-filled, or clears one back to empty. Never touches an occupied
  * human seat; the host removes a person by them leaving, not by overwriting their seat. */