feat: replacement effects in Module 4 (Armor absorption, Bolf Ramshield redirect)

Applying a Damage to one target now runs DAMAGE_STEPS = [redirect, armor]
first. A damageRedirect aura (Bolf Ramshield, fetched from the wiki) sends
damage meant for its owner's hero to the oldest such minion; Armor absorbs
damage to a hero before Health, logged as the new ArmorLost{player, amount}
just before a full-amount Damaged. Four new Module 4 tests; propagated to the
references of Modules 4-10 in both tracks; card schema, catalog, card JSON,
harness.md, Lessons 2, 4 and 5 updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

course/06-parser/reference/ts/src/engine/card.ts

@@ -36,8 +36,13 @@ export function triggerLabel(on: TriggerOn): string {
  * the aura owner's owner, activate `times` times each. `stacking` says how several
  * multipliers for the same trigger combine: `"max"` takes the largest (two copies of
  * a doubler still double); `"additive"` adds each copy's extra activations.
+ *
+ * `damageRedirect`: damage that would be dealt to the aura owner's hero is dealt to
+ * the aura's minion instead (see `DAMAGE_STEPS` in `queue.ts`).
  */
-export type Aura = { type: "triggerMultiplier"; trigger: TriggerOn; times: number; stacking: "max" | "additive" };
+export type Aura =
+  | { type: "triggerMultiplier"; trigger: TriggerOn; times: number; stacking: "max" | "additive" }
+  | { type: "damageRedirect"; from: "friendlyHero"; to: "self" };
 
 /** Who an effect touches. */
 export type Target = "self" | "allMinions" | "allOtherMinions" | "allOtherCharacters" | "enemyHero" | "chosen";