Add a typed platform package to decouple the frontend from Tauri (#539)

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

packages/platform/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "target": "es2021",
+    "lib": ["DOM", "DOM.Iterable", "ESNext"],
+    "strict": true,
+    "skipLibCheck": true,
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "noEmit": true
+  },
+  "include": ["src"]
+}