v0.8.5 — housekeeping from the audit, and the playtest line retired

The third release from the audit; nothing a player sees changes. CHANGELOG has the detail.

The 0.4.9 playtest line is no longer maintained (Jesse, 2026-09-29): the deploy rule that
existed for it is gone and #85 is moot. The table test (#39 #35 #42a #40) is closed — every
line of the checklist was met at a table. #46 is done and cannot regrow: the 36 unused
declarations are removed and `noUnusedLocals`/`noUnusedParameters` are on; two of them were
dead bot functions from rejected candidates the round said it had deleted. The documents no
longer teach `trainCapSlack` (a knob that throws), point at `as-built.md` (deleted in 0.8.2),
model `officeType` (the engine says `tier`) or describe `collisionOccurred` (never emitted);
the README's account of bot flags now matches the bot's. Five playtest saves committed in
`docs/` against the repository's own rule are in the ignored `playtests/`.

What the audit found and did not fix is written down as TODO #112-#117, each with its reason.
#112 is `docs/plans/structure.md`, the proposal for `http.ts`, `main.ts` and `check`. #117 —
`/api/save` hands a seat the seed mid-game — waits on a conversation.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FrCWubm9GAftYCm2hWdKwK

src/sim/board-svg.ts

@@ -113,14 +113,6 @@ export function divisionSvg(nodes: DivisionView[], roster?: DivisionRoster | nul
   const CHIP_Y = RAIL_Y - 10;
   const BELOW_Y = RAIL_Y + 13;
   const GAP = 6;
-  /**
-   * ONE FIXED SLOT PER A/D TRACK, so the Office Running Track cell is drawn wide enough to hold
-   * them without spilling onto its neighbours (docs/plans/switching-paths.md — "The Roster Pass").
-   * Sized by CAPACITY, not by how many are occupied right now: a cell drawn for the trains it HAS
-   * holds still as they come and go, where sizing by occupancy moved the East Division Point (and
-   * everything past it) sideways every time an A/D track filled or cleared.
-   */
-  const CHIP_W = 54;
   /**
    * Room for the buffer stops. THE LABELS NO LONGER LIVE OUT HERE.
    *

src/sim/bot.ts

@@ -91,19 +91,6 @@ function because(reason: string, intent: Intent): Intent {
   return intent;
 }
 
-/**
- * KNOBS FOR A/B MEASUREMENT, and nothing else.
- *
- * A heuristic change has to be measured against the bot it replaces, over the SAME deals — and
- * editing the bot between runs makes that impossible to do honestly, because the two sides of the
- * comparison never exist at once. Every flag here is off by default, so `makeDeveloperBot({})` is
- * byte-identical to the bot that came before this existed.
- *
- * TEMPORARY BY CONSTRUCTION. When a flag measures well it becomes the default and the flag is
- * deleted in the same commit; when it measures badly it is deleted with its finding recorded in the
- * changelog. What must not happen is a bot that accumulates switches nobody can account for — a
- * heuristic with no measurement attached is exactly what this machinery exists to prevent.
- */
 /**
  * ABLATIONS, for re-measuring the heuristics that are now the bot's default play.
  *
@@ -356,40 +343,13 @@ function committedTrains(s: GameState): number {
  *
  * §7 lets you play as many train cards as you draw, and a train that arrives with nowhere to stand
  * is an automatic collision (Gap 2d) — so the two rules together make a train card actively harmful
- * once the A/D tracks are spoken for. Off unless `trainCapSlack` is set.
+ * once the A/D tracks are spoken for. `noTrainCap` switches the cap off for re-measurement.
  */
 function trainWouldOverfillTheOffice(s: GameState, player: PlayerIndex, tweaks: BotTweaks): boolean {
   if (tweaks.noTrainCap) return false;
   return committedTrains(s) >= officeProfile(areaOf(s, player).tier).adTracks;
 }
 
-/**
- * Would running here leave the engine buried among its own cars?
- *
- * Cars met on a FORWARD move couple onto the nose (§A.3), which pushes the engine back through its
- * own train — `carsCoupled` moves `engineAt` by the number taken. So the engine ends up buried
- * whenever it had cars behind it already and picks up more in front, and §8.2 then refuses to let
- * the train leave the Office. Only trains care: a local crew has nowhere it must depart from.
- *
- * Asked of the engine's own destination list, so the count is the count that will really couple.
- */
-function wouldBuryTheEngine(
-  s: GameState,
-  player: PlayerIndex,
-  move: Extract<Intent, { type: 'switch.move' }>,
-): boolean {
-  const tray = s.trays.get(move.trayId);
-  if (!tray || tray.trainNumber === null) return false;
-  if (tray.position.at !== 'grid') return false;
-  if (move.reverse) return false; // cars taken while backing up couple BEHIND the engine
-  const len = tray.consist.length;
-  if (len === 0 || tray.engineAt >= len) return false; // nothing behind the engine to bury it against
-
-  const dest = destinationsFor(s, player, move.trayId, tray.position.coord, false).find(
-    (d) => d.coord.row === move.to.row && d.coord.col === move.to.col,
-  );
-  return (dest?.couples.length ?? 0) > 0;
-}
 
 function chooseLocalOption(
   s: GameState,
@@ -1427,8 +1387,6 @@ function followThrough(
           (i): i is Extract<Intent, { type: 'draw.fromDepartment' }> =>
             i.type === 'draw.fromDepartment' && isWorthTaking(s, player, i.slot, tweaks),
         );
-        // Best-ranked pile rather than the first that qualifies: an Office card and a train card
-        // both "qualify", and only one of them stops the collisions.
         // Best-ranked pile, not the first that qualifies. Measured as a near no-op — an Office card
         // and a train card are face up together 1.6 decisions a game — but ranking them is what the
         // ranking function is for, and a coin flip on the card that decides whether the district
@@ -1980,19 +1938,6 @@ function sidingsWorthCollecting(
   return out;
 }
 
-/** Cars standing on ordinary track that some facility would actually take. */
-function strandedWantedCars(s: GameState, player: PlayerIndex): { row: number; col: number }[] {
-  const out: { row: number; col: number }[] = [];
-  const tray = trayOf(s, player);
-  if (!tray || tray.consist.length >= MAX_CONSIST) return out;
-  for (const [key, card] of areaOf(s, player).grid) {
-    if (card.facility || card.standing.length === 0) continue;
-    if (!card.standing.some((c) => facilitiesWanting(s, player, c).length > 0)) continue;
-    const [row, col] = key.split(',').map(Number);
-    out.push({ row: row!, col: col! });
-  }
-  return out;
-}
 
 function trayOf(s: GameState, player: PlayerIndex) {
   for (const tray of s.trays.values()) {

src/sim/compare.ts

@@ -251,7 +251,7 @@ if (isMain) {
   const tweaks = parseTweaks(args);
 
   if (Object.keys(tweaks).length === 0) {
-    console.error('nothing to compare — pass at least one tweak, e.g. trainCapSlack=1');
+    console.error(`nothing to compare — pass at least one ablation, e.g. noValueLays=1 (one of: ${[...BOOLEAN_TWEAKS].join(', ')})`);
     process.exitCode = 1;
   } else {
     console.log(formatPaired(compare(tweaks, games, length)));

src/sim/replay.ts

@@ -19,25 +19,22 @@
 import { writeFileSync } from 'node:fs';
 
 import { advance } from '../engine/advance.ts';
-import { applyIntent, areaOf, facilityCarType, laborersLeft, portersLeft } from '../engine/apply.ts';
+import { applyIntent } from '../engine/apply.ts';
 import type { GameLength } from '../engine/content.ts';
 import {
   DEFAULT_MAX_COLLISIONS_PER_DAY,
   DEFAULT_MAX_COLLISIONS_TOTAL,
-  MAINLINE_PROFILES,
   collectiveRevenueFloor,
   lengthProfile,
-  officeProfile,
 } from '../engine/content.ts';
 import type { GameEvent } from '../engine/events.ts';
-import type { Intent } from '../engine/intents.ts';
 import { legalActions } from '../engine/legal.ts';
 import { createGame } from '../engine/setup.ts';
-import type { Facility, GameConfig, GameState } from '../engine/state.ts';
+import type { GameConfig } from '../engine/state.ts';
 import { actingPlayer } from '../engine/state.ts';
 import { reasonSentence } from '../web/panels.ts';
 import { developerBot, lastChoiceReason } from './bot.ts';
-import { carLabel, cuesFor, idleNote, isVisible, narrate } from './narrate.ts';
+import { cuesFor, idleNote, isVisible, narrate } from './narrate.ts';
 // The view-model lives in its own module so the browser build can import it without dragging in
 // this file's Node dependencies. Re-exported because tests and the web app import it from here.
 export type { CellView, DivisionView, FacilityView, Frame, Decision, TrainChip } from './view.ts';

src/sim/save-replay.ts

@@ -18,7 +18,7 @@
  *
  * Run with:
  *   node src/sim/save-replay.ts 400 --top 3
- *   node src/sim/save-replay.ts 400 --top 3 trainCapSlack=0
+ *   node src/sim/save-replay.ts 400 --top 3 noValueLays=1
  */
 
 import { readdirSync, unlinkSync, writeFileSync } from 'node:fs';

src/sim/view.ts

@@ -889,14 +889,14 @@ export function describeDecision(
     groups.set(o.type, list);
   }
   const rejected = [...groups.entries()]
-    .map(([kind, list]) => ({ kind, count: list.length, detail: sampleDetail(s, kind, list) }))
+    .map(([kind, list]) => ({ kind, count: list.length, detail: sampleDetail(s, list) }))
     .sort((a, b) => b.count - a.count);
 
   return { actor, chose: describeIntent(s, chosen), why, rejected, totalOptions: options.length };
 }
 
 /** A short, concrete example of what a group of rejected options would have done. */
-function sampleDetail(s: GameState, kind: string, list: Intent[]): string {
+function sampleDetail(s: GameState, list: Intent[]): string {
   // Deduplicate by DESCRIPTION. Orientation variants and repeated copies of a card describe
   // identically, so the raw list reads "play Overpass at (0,0)" three times over and hides the
   // actual range of choices — the opposite of what this panel is for.