refactor: convert SPA to multi-page architecture

- Add scene_onboarding.html, scene_dashboard.html, scene_settings.html
- Add onboarding.js, dashboard.js, settings.js scripts
- Update vite.config.js for multi-page build
- Navigation via window.location.href between pages
- Bottom nav bar on dashboard only

package.json

@@ -0,0 +1,20 @@
+{
+  "name": "chakmate",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview",
+    "tauri": "tauri"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "@tauri-apps/cli": "^2.0.0",
+    "autoprefixer": "^10.4.20",
+    "postcss": "^8.5.0",
+    "tailwindcss": "^3.4.17",
+    "vite": "^5.4.0"
+  }
+}