v0.8.0.9 — the bot plans its switching turn, stops wasting its draws, and the engine walks each route once

The developer bot, re-measured decision by decision against the bot before it,
goes from about -0.3 revenue a game to about 4.8:

- plans the whole switching turn before its first Move (sim/switch-planner.ts),
  +2.89 over 1600 paired seeds; closes TODO #53
- takes a face-up card only if it could play it, +1.52 over 1600 seeds
- stops running Second Sections by accident in the New Train phase, +0.32
- lays track by what the district can do afterwards, +0.12 over 6400 seeds,
  run-arounds in 22 of 60 districts against 9

The engine is 2.8x faster with play proven identical: a route cache scoped to
one unchanged position, applyIntent split into prepareIntent + commitEvents,
and less allocation in exploreMoves. npm test now leaves out the bot
simulations, which run as npm run test:sim.

No rule changed; games in progress resume. Rejected candidates and the
Second Section card question are in CHANGELOG.md and TODO.md (#104-#106).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017nnuCv8UodHucFfx3LWEoX

README.md

@@ -56,7 +56,8 @@ deliberately no longer names one: it went stale for six releases.
 Balance is *not* where it should be, and this file no longer quotes a figure for it. It used to say
 "the developer bot averages 7.0 Revenue against a target of 20", which stopped being true the moment
 the transit rule it names was defaulted to off — that rule was worth ~5.4 of the 7.0, for traffic
-nobody had to work. Measured at the current defaults the bot means about **zero**.
+nobody had to work. Measured at the current defaults the bot meant about **zero** until it began
+planning its switching turns (2026-09-14), which put it near **2.8**.
 
 The three rates — passenger per coach, freight per load, train per transit — are **settings fixed when
 the game is dealt**, along with the opening hand and where an Extra may start, so the economy can be
@@ -102,7 +103,8 @@ separate thing: it assembles the static SITE into `dist/`.)
 
 ```sh
 npm install
-npm test          # node --test
+npm test          # node --test, everything except the bot simulations — run after every change
+npm run test:sim  # test/sim.test.ts, the bot simulations (~7 min) — run after a bot or balance change
 npm run typecheck # tsc --noEmit
 ```