feat: module 04 interceptors

Trigger multipliers as aura data on cards, snapshotted by an Aura Update
(Other) after each Death Creation Step and on summon, and applied by one
generic routine (activations) when each queued trigger starts. Baron
Rivendare is content only (stacking "max"); Brann Bronzebeard is the
content-only Expansion Drop. Adds play (now required) and Battlecry.

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

course/04-interceptors/reference/ts/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "systemic-design-workspace",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "test": "vitest run",
+    "typecheck": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "typescript": "^5.6.0",
+    "vitest": "^2.1.0"
+  }
+}