v0.4.9 — X,Y coordinates, no-switching can still clear the mainline, Q3 corrected, a clearance bug, three sounds, and the box art

A playtest review of seed 58228926 (day 6), plus one long-standing display complaint and the
first real audio beyond a placeholder.

- Coordinate labels read X,Y everywhere shown to a player, not the internal Y,X storage order.
  Display-only.
- "No switching" now means may not add or drop cars, not "never touch it" — these trains can
  still be moved onto Secondary Track to clear the mainline.
- Q3 corrected: Expedite governs WHERE a train may be left standing, not WHEN it leaves. The
  forced same-Stage departure is gone; a new fault costs 1 Revenue if an expedited train is left
  off the station when a Mainline Phase begins. Resolves "3/4 Express prints a rule it can never
  use" as a side effect.
- evaluateClearance now checks every occupant on a Mainline card before offering a judgment
  call, instead of returning on whichever it found first — found while explaining a playtest
  report, fixed with a regression test.
- Three new synthesised sounds: arrive, depart, crash.
- The splash page shows the box art.

Full detail, measurements and reasoning in CHANGELOG.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FvU99NEakShRMg3nN3fHAZ

test/train-rules.test.ts

@@ -76,13 +76,23 @@ const coach = (loaded = false): RollingStock => ({ type: 'coach', loaded });
 // ---------------------------------------------------------------------------
 
 describe('§7 — no switching', () => {
-  it('refuses every switching act to a train whose card forbids it', () => {
+  it('still allows a plain move — "no switching" means no adding or dropping cars', () => {
     // Six cards print it: both expresses, the Light Engine, Campaign, Circus and Military trains.
-    // Moving, setting out and sorting are all switching, so all three are refused.
+    // A train held at the Office may still need to clear onto Secondary Track ahead of other
+    // traffic, so a move that couples nothing is legal.
     const s = game();
     switching(s, 1, false, [boxcar()]);
+    assert.equal(check(s, 0, { type: 'switch.move', trayId: 't', to: west(s), reverse: false }), null);
+  });
 
-    assert.equal(check(s, 0, { type: 'switch.move', trayId: 't', to: west(s), reverse: false }), 'NO_SWITCHING');
+  it('refuses a move that would couple a car, and refuses dropping and sorting outright', () => {
+    const s = game();
+    switching(s, 1, false, [boxcar()], [boxcar()]);
+
+    assert.equal(
+      check(s, 0, { type: 'switch.move', trayId: 't', to: west(s), reverse: false }),
+      'PICKUP_NOT_ALLOWED',
+    );
     assert.equal(check(s, 0, { type: 'switch.dropCars', trayId: 't', count: 1 }), 'NO_SWITCHING');
     assert.equal(check(s, 0, { type: 'switch.sortConsist', trayId: 't', order: [0] }), 'NO_SWITCHING');
   });