feat(slay-the-spire-like): support source entity in effect targeting

Update `getEffectTargets` to accept a `sourceEntityKey`. This allows
"self" targets to correctly resolve to the entity triggering the
effect (e.g., a player or a specific enemy) rather than defaulting
to a hardcoded player reference.

tests/samples/slay-the-spire-like/combat/triggers.test.ts

@@ -382,12 +382,6 @@ describe("desert triggers", () => {
         }),
       );
       const triggers = getTriggers();
-      const stormEffect = createEffect("storm", "permanent");
-
-      ctx._state.produce((draft) => {
-        const enemy = draft.enemies[0];
-        enemy.effects.storm = { data: stormEffect, stacks: 2 };
-      });
 
       await triggers.onEnemyIntent.execute(ctx, { enemyId: "风暴之灵-0" });