Say who is playing, what you can press, and where you are in the Stage

Mostly presentation, plus one rules fix found on the way.

TODO.md

@@ -93,6 +93,21 @@ target is settled and freight carries its intended share.
 
 ## Not yet built
 
+- [ ] **Let the game join a call and talk to the table.** Long-term. If the game could join a Zoom,
+      Teams or Jitsi call and post into its chat, it could carry the whole table's shared state
+      without anyone alt-tabbing: the history of actions as they happen, and a prompt when someone
+      is holding the game up — "Now waiting on player Alice to complete the Cargo phase."
+      - Further out, audio into the same call: a crash when a collision happens, a bell as the Stage
+        clock turns over.
+      - Further out still, a nudge on a timer — if a player has not moved within some interval, the
+        game says so, by beep or by spoken line: "Still waiting on Alice to complete the Cargo
+        phase." That turns the turn chart's "waiting on" chip into something a distracted table
+        actually notices.
+- [ ] **Multiplayer train make-up is a round, not one player's job.** When a new train is built,
+      players take turns adding cars to the consist; in solitaire one player does all of it. The
+      engine currently has no per-player turn within the New Train phase, so this is unbuilt rather
+      than wrong.
+
 - [ ] **Action cards (10) and Space-use cards (12).** Genuinely multiplayer-only — they are played AT
       an opponent. Rejected with `NOT_IMPLEMENTED`.
 - [ ] **Multiplayer proper.** The engine runs 2–5 player games and the bot plays them, but there is no