chore: init v2 project scaffold

- Add electron-vite + Vue 3 + TypeScript build config
- Add .gitignore with legacy/ exclusion
- Add AGENTS.md with architecture & dev commands
- Update README.md

tsconfig.node.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "outDir": "./out",
+    "types": ["node"],
+    "composite": true
+  },
+  "include": ["src/main/**/*", "src/preload/**/*", "electron.vite.config.ts"]
+}