v0.8.0 — the board replays what everyone else did, instead of arriving rearranged

TODO #13, #15 and #18 — Gitea#20 steps 2-4 pointed at a seated player's own screen.
Every accepted intent, and every automatic phase that does anything, becomes an
ordered presentation step. A bot's whole switching turn used to land in one push;
now it arrives as a run of steps, the district panel follows whoever is acting,
and a [N behind] … [Skip] row says how far the board is from the game.

Solitaire runs the same path — one collector inside submit(), which both session
kinds already funnel through — which is where its automatic phases finally get a
visible beat.

Dwell is assigned by kind: switching holds the screen, turn bookkeeping costs
nothing, and the clock turning over earns the beat. Tunable per viewer without a
rebuild, and off entirely at pace 0.

Also: switching was the one class of action logging unattributed, and now names
its train. Reasoning, measurements and the three things that turned out wrong are
in CHANGELOG.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X6cF1iYvJ1kNmzYBzu4QX6

src/web/game.ts

@@ -23,7 +23,7 @@
  * folding events does not rebuild a game — `protocol.md` §3.)
  */
 
-import { pump } from '../engine/advance.ts';
+import { advance, pump } from '../engine/advance.ts';
 import { applyIntent } from '../engine/apply.ts';
 import type { GameEvent } from '../engine/events.ts';
 import type { Intent } from '../engine/intents.ts';
@@ -33,6 +33,8 @@ import type { CardId, GameConfig, GameState, PlayerIndex } from '../engine/state
 import { overHandLimit as overHandLimitOf } from '../engine/state.ts';
 import { playerAtSeat } from '../engine/state.ts';
 import { cuesFor, narrate } from '../sim/narrate.ts';
+import { collectStep, newCollector } from '../sim/display-step.ts';
+import type { DisplayCollector } from '../sim/display-step.ts';
 // Import from the view module, NOT replay.ts — replay.ts writes files and reads process.argv,
 // which would pull node:fs into a browser bundle.
 import {
@@ -276,6 +278,16 @@ export type Game = {
    * having taken a turn to cause it.
    */
   announced: string | null;
+  /**
+   * ORDERED PRESENTATION STEPS — v0.8.0, TODO #13. One per accepted intent, so a player can WATCH
+   * what everyone else did rather than find the board already rearranged.
+   *
+   * Accumulated here beside `log`, `cues` and `announced` and drained the same way, because that is
+   * how this file already hands things to whatever is displaying the game. Filled by `submit()`
+   * alone, which is what makes it identical for solitaire and multiplayer and inert during replay —
+   * see `sim/display-step.ts`.
+   */
+  display: DisplayCollector;
 };
 
 /** How each intent kind is introduced in the action list, in the order they should appear. */
@@ -311,7 +323,7 @@ export const SOLO_PLAYER = 'Solitaire';
 
 export function newGame(seed: number, config: GameConfig = SOLO_CONFIG): Game {
   const state = createGame({ id: `web-${seed}`, seed, config, playerNames: [SOLO_PLAYER] });
-  const game: Game = { state, seed, history: [], log: [], cues: [], scheduled: null, justDrawn: null, announced: null };
+  const game: Game = { state, seed, history: [], log: [], cues: [], scheduled: null, justDrawn: null, announced: null, display: newCollector() };
   // A history that opens mid-Stage reads as though something was missed. Say what the game IS
   // first, then let the clock take over.
   game.log.push({ text: 'Game Begins', tone: 'start' });
@@ -330,7 +342,7 @@ export function newGame(seed: number, config: GameConfig = SOLO_CONFIG): Game {
  */
 export function newMultiplayerGame(seed: number, config: GameConfig, playerNames: string[]): Game {
   const state = createGame({ id: `mp-${seed}`, seed, config, playerNames });
-  const game: Game = { state, seed, history: [], log: [], cues: [], scheduled: null, justDrawn: null, announced: null };
+  const game: Game = { state, seed, history: [], log: [], cues: [], scheduled: null, justDrawn: null, announced: null, display: newCollector() };
   game.log.push({ text: 'Game Begins', tone: 'start' });
   /**
    * NO SEED AT A TABLE WITH MORE THAN ONE SEAT (Gitea#20 step 1).
@@ -1105,11 +1117,69 @@ export function submit(game: Game, intent: Intent, as: PlayerIndex | null = null
     return false;
   }
   game.history.push(intent);
+  /**
+   * THE HIGH-WATER MARK FOR THIS STEP'S NARRATION (v0.8.0).
+   *
+   * Taken here rather than read from `session.ts`'s `sentLines`, which is per-seat and is MUTATED
+   * by `linesSince()` as a side effect of building a push — so it cannot answer "what did this one
+   * intent say?". `submit` brackets the whole thing, `record` and `drain` below are the only things
+   * that append, and the slice after them is exactly this intent's narration including whatever
+   * automatic phases it drained.
+   */
+  const saidFrom = game.log.length;
   record(game, result.events, actor);
-  drain(game);
+  collectStep(game.display, game.state, actor, intent.type, game.log.slice(saidFrom));
+  drainStepping(game);
   return true;
 }
 
+/**
+ * `drain()`'s STEPPED TWIN — TODO #18, and the reason this is not just `drain(game)`.
+ *
+ * `pump()` runs every automatic phase between one click and the next and `drain()` records the whole
+ * batch at once, so New Train, the Mainline and the shift change are never drawn at all: trains
+ * cross the Division in a single jump. Stepping `advance()` one call at a time and collecting after
+ * each is what gives those phases a visible beat, which is exactly what TODO Reference · #18 says is
+ * needed — *"a minimum dwell time on its own therefore fixes nothing"*.
+ *
+ * IDENTICAL BEHAVIOUR TO `drain()`, deliberately. The same `advance()` calls in the same order
+ * produce the same state; `record()` is called per phase rather than per batch, which is equivalent
+ * because `cuesFor` is a pure per-event map with no cross-event state and `record`'s other outputs
+ * (`scheduled`, `justDrawn`, `announced`) are last-wins in event order either way.
+ *
+ * A PHASE THAT DID NOTHING PRODUCES NO STEP. Jesse, 2026-09-09: *"if nothing happens during a phase
+ * then we shouldn't lose time to it."* Narrating nothing is the test for that — an empty phase adds
+ * no lines, so it is skipped rather than given a dwell to sit through.
+ *
+ * `drain()` itself is untouched, and must stay that way: `fromSave`, `fromMultiplayerSave` and
+ * `undo` all use it, and the collector staying off those paths is what keeps a replay from
+ * re-emitting a whole game as steps.
+ */
+function drainStepping(game: Game): void {
+  for (let i = 0; i < 10_000; i++) {
+    const from = game.log.length;
+    const r = advance(game.state);
+    record(game, r.events);
+    /**
+     * THE TEST IS THE EVENT LIST, NOT THE LOG — and getting that wrong drifted the board.
+     *
+     * `record()` deliberately drops `actorChanged` before narrating, so a phase whose only effect is
+     * handing the turn to the next player grows no lines at all. Collecting only when the log grew
+     * therefore skipped those, and the last step's frame was then a position behind the real one:
+     * the animated board ended a turn out of step with the game (`actor: 2` where the game said 1).
+     *
+     * A step whose narration is empty still carries the board. It simply costs no time to show —
+     * `dwellForStep` gives a silent step a dwell of zero — which is the same rule that collapses an
+     * empty phase, arrived at from the other direction.
+     */
+    if (r.events.length > 0) {
+      collectStep(game.display, game.state, null, 'phase', game.log.slice(from));
+    }
+    if (r.needsInput || game.state.status === 'finished') return;
+  }
+  throw new Error('phase driver failed to settle — probable infinite loop');
+}
+
 /**
  * Which cards in hand can be played RIGHT NOW, in hand order.
  *