feat: add shared TypeScript types for Game, Documentary, Chapter

Create @afterlife/shared package with type definitions for the core
domain models (Game, Documentary, Chapter) and Strapi API interfaces
(StrapiMedia, StrapiResponse, StrapiListResponse).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/shared/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "declaration": true,
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src"]
+}