v0.4.9d — three playtest bugs: a train that looked gone, an unload that ignored the pick, a hang that wasn't one

Patched directly onto 0.4.9a rather than the in-progress 0.5.0 line.

A switching train vanished from the board the moment it left the Office. `selectedTrain` in
`officeSvg` (board-svg.ts), which gates whether a card draws a train's crew badge, was only ever
assigned inside the `cell.adTracks !== null` branch — true for the Office card alone. A train
standing anywhere else, which is everywhere it stands while actually being switched, drew no badge
at all. Game state was never affected; confirmed against the reported save with the engine directly.
Fix hoists the assignment out of the guard so it runs for any card with a train on it.

Unloading always took the westmost car, whichever one was picked. `laborer.beginUnload` carried the
player's chosen `carIndex`, and `check()` validated that specific car, but the `unloadBegan` event
it produced carried only the car's type — the reducer that performs the swap re-derived the target
with `industryTrack.cars.findIndex(c => c.loaded)`, which always answers the first loaded car in
track order regardless of what was requested. Fix adds `carIndex` to the event and uses it directly.

A legal decision could render with zero buttons, which looked exactly like a hang. The "where does
this Extra start" decision is titled by `trainCardTitle`, beginning "Making up Extra X22…" — the
same prefix `renderActions()` stripped from the action list on the assumption it only ever belonged
to the separate yard-chip car-placement panel. With no tray yet being filled, that panel is null, so
nothing rendered the Extra's decision either: a legal, correctly-computed option with no button
anywhere on the page. Replaying the reported save found no engine deadlock at any step — the engine
always had a move. Fix matches the exact title of the one group the yard-chip panel covers instead
of a title-prefix regex.

New tests for all three: a train parked on an ordinary facility card must draw its crew badge; three
differently-typed loaded cars, unloading index 2, must leave indices 0 and 1 alone; the existing
softlock regression test now mirrors the real render filter instead of only the raw menu, plus a
deterministic test for the exact reported scenario. 590 tests, 0 failures.

CHANGELOG.md

@@ -19,6 +19,81 @@ page as `v0.1.0 · <sha> · <date>`, so what is deployed can always be identifie
 
 ---
 
+## 0.4.9d — 2026-08-21
+
+Three bugs from the same playtest session, patched directly onto 0.4.9a rather than the in-progress
+0.5.0 line: a display bug that made a switching train look like it had vanished, an engine bug that
+silently ignored which car the player chose to unload, and a UI bug that could render a legal
+decision with zero buttons — indistinguishable from a hang.
+
+### A switching train vanished from the board the moment it left the Office
+
+**REPORTED:** Train 3 stood at the Office; dropping the loaded boxcar off the back at the Freight
+House made the train "vanish off the face of the earth," regardless of which way it moved
+afterward. The game state was never wrong — replaying the reported save
+(`docs/station-master-seed116956197-day2.json`) through the engine directly showed `tray3` fully
+intact, in the right place, with the right consist, for the rest of the game. Nothing was ever lost
+from `state.trays`.
+
+The bug was in `officeSvg` (`board-svg.ts`): `selectedTrain` — the value that decides whether a
+card draws a train's crew badge (its label, engine arrow, and cars) — was assigned only inside the
+`cell.adTracks !== null` branch, which is true for the Office card and nothing else. A train
+standing on any other card, which is every card it stands on while actually being switched, got no
+badge at all. It disappeared on the very first move off the Office, not only at the Freight House —
+that was simply the first place a player was likely to pause and look. Traced to the Roster Pass
+(37b1e5b), which rewrote `CellView.train` into `CellView.trains[]` to show every train sharing the
+Office's A/D tracks and, in doing so, nested the general consist-drawing logic inside that
+Office-only branch instead of leaving it to run for any card with a train on it.
+
+**Fixed** by hoisting the `selectedTrain` assignment out of the `adTracks !== null` guard so it
+runs for every card; the A/D roster-chip loop itself stays inside the guard, since only the Office
+has more than one A/D track to draw chips for. New test: a train parked on an ordinary facility
+card, `adTracks: null`, now has to draw its crew badge — it did not before this fix.
+
+### Unloading always took the westmost car, whichever one was picked
+
+**REPORTED:** three loaded cars stood at a Freight House; asking to unload the east (right-hand)
+car unloaded the west one instead, every time, no matter which car was actually chosen.
+
+`laborer.beginUnload` already carried the player's choice as `carIndex`, and `check()` validated
+that specific car — but the event it produced, `unloadBegan`, carried only the car's `carType`, not
+which one it was. The reducer that actually performs the swap re-derived the target itself with
+`industryTrack.cars.findIndex(c => c.loaded)`, which always answers the first loaded car in track
+order regardless of what was requested — so the player's choice was thrown away between `check` and
+the reducer, and the westmost loaded car came off every time.
+
+**Fixed** by adding `carIndex` to the `unloadBegan` event and using it directly in the reducer
+(`src/engine/apply.ts`, `case 'unloadBegan'`), instead of re-deriving a car by scanning for
+`loaded`. New test in `apply.test.ts`: three loaded cars of three different types, asking to unload
+index 2 (east) now leaves indices 0 and 1 alone and empties exactly the one requested — it did not
+before this fix.
+
+### A legal decision could render with zero buttons — the game looked hung
+
+**REPORTED:** working the Freight House mid-cycle (unloading three cars, then reloading them), the
+game "seemed to have hung up. Cannot advance." No trains were on the Division or the Limits.
+
+Replaying the reported save turned up no engine deadlock at any point — every step had a legal
+action — but the exact final state (an Extra train due to start, no tray yet being made up) exposed
+a UI bug: `newTrain.startExtra`'s action group is titled by `trainCardTitle`, which begins "Making
+up Extra X22…" — the same prefix `renderActions()` (`main.ts`) used to strip from the action list on
+the assumption it always belonged to the separate yard-chip car-placement panel. With no tray being
+filled yet, that panel (`menu.makeUp`) is `null`, so nothing else rendered the Extra's "choose where
+it starts" decision either — a legal, present, correctly-computed option with no button anywhere on
+the page. Clicking nothing did nothing, which is indistinguishable from a hang.
+
+**Fixed** by matching the exact title of the one group `menu.makeUp` actually covers
+(`g.title !== menu.makeUp?.title`) instead of a title-prefix regex, so any other group that happens
+to start "Making up …" — however it got that title — stays on screen. The existing softlock
+regression test (`never strands the player with a legal move and no way to make it`) now mirrors the
+real render filter instead of only checking the raw menu, so this class of bug fails that test
+directly; a new deterministic test constructs the exact reported scenario (a pending Extra, no
+active make-up) and asserts its group survives the filter.
+
+590 tests, 0 failures.
+
+---
+
 ## 0.4.9a — 2026-08-20
 
 Four small tweaks to the splash page (`index.html`, `splash.ts`), no engine changes.