Expand game engine, replay, tests, and documentation

docs/rules/rules-v0.2.md

@@ -1,5 +1,11 @@
 # Station Master — Rules v0.2
 
+> **⚠ Superseded in part.** Four design files recovered on 2026-07-30 (`Deck cards2.xlsx`,
+> `Mainline Cards.pdf`, `Trains3.pdf`, `tracks.png`) replace much of §12 and parts of §7, §8 and
+> §11. Where they conflict, **the design wins**. Read
+> [`implications.md`](implications.md) alongside this document — it records what changed, the nine
+> answers that settled the open questions, and what is implemented.
+
 > **Status: working ruleset.** This is [`rules-v0.1.md`](rules-v0.1.md) — the faithful transcription
 > of the prototype PDFs — with the seven gaps from [`open-questions.md`](open-questions.md) resolved
 > and integrated in place.
@@ -783,9 +789,9 @@ with a run-around (bypass) track in your Secondary Trackage:
 - **Reduced visibility.** The first three Stages (midnight through 4am) and the last two (8pm through
   10pm) are night operations. You get only five Moves in the Local Operations Phase during these
   Stages.
-- **"Sister" trains.** Trains run with counterparts — 1 & 2, 3 & 4, and so on. Pull all even train
-  cards (2 through 12) from the deck and set them aside. When the companion odd-numbered train is
-  drawn and played, bring the Sister Train in as well. Does not include Extras.
+- ~~**"Sister" trains.**~~ **Removed.** The design's **Second Section** card does this properly: it
+  is played on a train that is due out, and an identical train runs immediately behind it. See
+  [`implications.md`](implications.md) Q9.
 - **Employee Rotation.** At the end of the Day, all players move one chair to the left and take over
   the next station up the line, taking their points and the Fedora with them.
 - **Emergency Toolbox.** Each player starts with a RED FLAG card, bringing his hand to four; he must