A duel server: rooms, seat tokens, ledgers, and resolution when all have moved

Plain HTTP for actions and a websocket that only says "fetch again". A
room is its append-only ledger replayed from the top; the engine is
deterministic given the seed and the recorded inputs. Each seat sees a
view filtered to what the rules let it know. Bot seats are filled at
resolution time.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/lib/game/resolve.ts

@@ -153,8 +153,8 @@ export function resolveTurn(previous: GameState, inputs: Record<WizardId, TurnIn
 	/** Time-stop entries and log lines belong to the turn just played. */
 	const turn = actor ? state.turn - 1 : state.turn;
 	const events: string[] = [];
-	const log = (text: string, kind: LogKind = 'info', surface = kind !== 'gesture' && kind !== 'damage') => {
-		state.log.push({ turn, kind, text });
+	const log = (text: string, kind: LogKind = 'info', surface = kind !== 'gesture' && kind !== 'damage', hiddenFrom?: WizardId[]) => {
+		state.log.push(hiddenFrom?.length ? { turn, kind, text, hiddenFrom } : { turn, kind, text });
 		if (surface) events.push(text);
 	};
 	const rng = () => nextRandom(state);
@@ -256,7 +256,7 @@ export function resolveTurn(previous: GameState, inputs: Record<WizardId, TurnIn
 		w.history.push({ left, right, turn, phase: entryPhase, hiddenFrom });
 		if (left === 'P' && right === 'P') w.surrendered = true;
 		const prefix = entryPhase === 'haste' ? `${w.name}, hastened, adds` : `${w.name}:`;
-		log(`${prefix} left ${lone(left, right)}, right ${lone(right, left)}.`, 'gesture');
+		log(`${prefix} left ${lone(left, right)}, right ${lone(right, left)}.`, 'gesture', false, hiddenFrom);
 	};
 	/** History indexes of the entries each acting wizard made this turn. */
 	const entries: Record<WizardId, number[]> = Object.fromEntries(seats.map((id) => [id, []]));

src/lib/game/state.ts

@@ -107,6 +107,8 @@ export interface LogEntry {
 	turn: number;
 	kind: LogKind;
 	text: string;
+	/** Wizards who may not read this line: it describes gestures they could not see. */
+	hiddenFrom?: WizardId[];
 }
 
 /** What a reveal did to each wizard's health, for the result strip. */

src/lib/game/view.ts

@@ -0,0 +1,16 @@
+// What one wizard is allowed to know. Gestures made while they were blind, or
+// while the other wizard was invisible, are unknown to them; the log lines that
+// describe those gestures are withheld too. Spells cast are always visible, as
+// the rules say.
+
+import { visibleHistory, type GameState, type WizardId } from './state';
+
+export function viewFor(state: GameState, viewer: WizardId): GameState {
+	const view = structuredClone(state);
+	for (const id of view.seats) {
+		if (id === viewer) continue;
+		view.wizards[id].history = visibleHistory(state, viewer, id);
+	}
+	view.log = view.log.filter((l) => !l.hiddenFrom?.includes(viewer));
+	return view;
+}