Waves spend their force as they travel (rev 24); bots wield Destroy Wall

Rules rev 24: a waterwall wave that finds a victim dist cells from its
source has only range-dist spaces of push left — a range-2 wave throws its
adjacent victim two spaces but a victim at its far edge only one, and
spent force never converts into crush damage. Applies to WATERWALL and
both STONE TO WATER waves; older revisions keep the flat full-range wash
so stored games replay unchanged.

Automatons now use DESTROY WALL on the march: two BFS distance maps (from
the bot, from its objectives) price every visible wall by the shortcut its
removal opens; the bot blasts when it saves 4+ steps of walking — or when
no road exists at all — never standing beside the blast unless trapped
and healthy. The card also leaves the shed pile: discardValue 2 -> 6.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0138A8CjeQRpvzKxuMfz1Bqc

packages/engine/test/expansion-terrain.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
-import { applyCommand, activePlayer, boardView, gameLos } from "../src/game";
-import { cellKey, SIDES, stepTarget, type Cell } from "../src/board";
+import { applyCommand, activePlayer, boardView, createGame, gameLos } from "../src/game";
+import { cellKey, edgeKey, SIDES, stepTarget, type Cell } from "../src/board";
 import type { CardInstance } from "../src/cards";
 import { eligibleCellsFor, sightedCellsFor, viewFor } from "../src/view";
 import { newExpansionGame as newGame, must, giveCard, emptyNeighborCell } from "./helpers";
@@ -212,3 +212,44 @@ describe("eligibility dimming mirrors the engine", () => {
     for (const k of lit) expect(seen.has(k)).toBe(true);
   });
 });
+
+describe("a wave's force is spent as it travels (rules rev 24)", () => {
+  /** Caster at B, one cell above A; the target wall is A's south edge, so
+   * the range-2 wave covers A (dist 0) and B (dist 1). */
+  function rig(deckRev: number, behind: "open" | "wall") {
+    const { state } = createGame({ playerIds: ["a", "b"], seed: 42, sets: ["basic", "expansion1"], deckRev });
+    const me = activePlayer(state);
+    const A = { x: 4, y: 5 }, B = { x: 4, y: 4 }, Bn = { x: 4, y: 3 }, Bnn = { x: 4, y: 2 };
+    for (const c of [A, B, Bn, Bnn]) expect(boardView(state).cells[cellKey(c)]).toBeTruthy();
+    state.edgeOverrides[edgeKey(A, "S")] = "wall";
+    state.edgeOverrides[edgeKey(A, "N")] = "open";
+    state.edgeOverrides[edgeKey(B, "N")] = behind;
+    state.edgeOverrides[edgeKey(Bn, "N")] = "open";
+    me.position = { ...B };
+    // The other wizard waits far outside the wave.
+    state.players.find((p) => p.id !== me.id)!.position = { x: 0, y: 9 };
+    const stw = giveCard(state, me.id, "stone-to-water", "SW", 0);
+    const after = must(state, me.id, {
+      type: "cast", instanceId: stw.instanceId, target: { kind: "edge", cell: A, side: "S" },
+    });
+    return { me: after.players.find((p) => p.id === me.id)!, B, Bn, Bnn };
+  }
+
+  it("a victim at the wave's far edge is carried one space, unhurt", () => {
+    const { me, Bn } = rig(24, "open");
+    expect(cellKey(me.position)).toBe(cellKey(Bn));
+    expect(me.life).toBe(15);
+  });
+
+  it("only unspent force crushes: one space of push blocked is one damage", () => {
+    const { me, B } = rig(24, "wall");
+    expect(cellKey(me.position)).toBe(cellKey(B));
+    expect(me.life).toBe(14);
+  });
+
+  it("older revisions keep the flat full-range wash for replay fidelity", () => {
+    const { me, Bnn } = rig(23, "open");
+    expect(cellKey(me.position)).toBe(cellKey(Bnn));
+    expect(me.life).toBe(15);
+  });
+});