Purge expansion2 card rows — a set this edition does not have

The 5e-inherited card database carried 85 rows tagged expansion2; 6e has
only the basic deck and Expansion Set #1, and buildDeck never dealt them.
They kept leaking into things that cite the database (rulebook text, the
IDIOT aid list), so the rows are gone and CardSet no longer names the set.
Other editions can reintroduce their own sets when they arrive.

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

packages/engine/src/cards.ts

@@ -4,7 +4,7 @@
 
 import cardsData from "../data/cards.json";
 
-export type CardSet = "basic" | "expansion1" | "expansion2";
+export type CardSet = "basic" | "expansion1";
 export type CardType =
   | "attack"
   | "neutral"

packages/engine/test/casting.test.ts

@@ -250,14 +250,6 @@ describe("stack discipline", () => {
     expect(applyCommand(state, defender, { type: "move", direction: "N" }).ok).toBe(false);
   });
 
-  it("unimplemented cards refuse to cast with a clear error", () => {
-    let { state } = newGame();
-    const caster = activePlayer(state);
-    const card = giveCard(state, caster.id, "bomb"); // expansion2: historical, never implemented
-    const result = applyCommand(state, caster.id, { type: "cast", instanceId: card.instanceId });
-    expect(result.ok).toBe(false);
-    if (!result.ok) expect(result.error).toMatch(/not implemented/);
-  });
 });
 
 describe("speedstone", () => {