Refactor combat targeting types and effect application logic in the
Slay the Spire-like sample.
- Update `getEffectTargets` to use `IntentEffectTarget` and more
descriptive target keys (e.g., `eachEnemy`, `randomEnemy`).
- Update `promptMainAction` to use `enemy` instead of `single` for
card target types.
- Refactor `addInstantEffectTriggers` to remove unused effect loading
and improve enemy/card instantiation logic