feat: initial isochrone desktop app (Electron + MapLibre + ORS)

- MapLibre GL v5 avec fond OpenFreeMap (vector tiles OSM gratuit)
- Isochrones via OpenRouteService API (voiture, vélo, piéton)
- Multi-isochrones colorées (jusqu'à 5 durées simultanées)
- Export PNG et GeoJSON
- Recherche de lieu via Nominatim
- Clé API ORS persistée en localStorage / .env

package.json

@@ -0,0 +1,51 @@
+{
+  "name": "isochrone-app",
+  "version": "1.0.0",
+  "description": "An Electron application with React and TypeScript",
+  "main": "./out/main/index.js",
+  "author": "example.com",
+  "homepage": "https://electron-vite.org",
+  "scripts": {
+    "format": "prettier --write .",
+    "lint": "eslint --cache .",
+    "typecheck:node": "tsc --noEmit -p tsconfig.node.json --composite false",
+    "typecheck:web": "tsc --noEmit -p tsconfig.web.json --composite false",
+    "typecheck": "npm run typecheck:node && npm run typecheck:web",
+    "start": "electron-vite preview",
+    "dev": "electron-vite dev",
+    "build": "npm run typecheck && electron-vite build",
+    "postinstall": "electron-builder install-app-deps",
+    "build:unpack": "npm run build && electron-builder --dir",
+    "build:win": "npm run build && electron-builder --win",
+    "build:mac": "electron-vite build && electron-builder --mac",
+    "build:linux": "electron-vite build && electron-builder --linux"
+  },
+  "dependencies": {
+    "@electron-toolkit/preload": "^3.0.2",
+    "@electron-toolkit/utils": "^4.0.0",
+    "@types/geojson": "^7946.0.16",
+    "maplibre-gl": "^5.21.1",
+    "zustand": "^5.0.12"
+  },
+  "devDependencies": {
+    "@electron-toolkit/eslint-config-prettier": "^3.0.0",
+    "@electron-toolkit/eslint-config-ts": "^3.1.0",
+    "@electron-toolkit/tsconfig": "^2.0.0",
+    "@types/node": "^22.19.1",
+    "@types/react": "^19.2.7",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^5.1.1",
+    "electron": "^39.2.6",
+    "electron-builder": "^26.0.12",
+    "electron-vite": "^5.0.0",
+    "eslint": "^9.39.1",
+    "eslint-plugin-react": "^7.37.5",
+    "eslint-plugin-react-hooks": "^7.0.1",
+    "eslint-plugin-react-refresh": "^0.4.24",
+    "prettier": "^3.7.4",
+    "react": "^19.2.1",
+    "react-dom": "^19.2.1",
+    "typescript": "^5.9.3",
+    "vite": "^7.2.6"
+  }
+}