feat: US-001 — scaffold NeuralDesk Electron + React app

- electron-forge 7 + Vite plugin (vite-typescript template)
- React 19 + TypeScript 5 strict mode
- TanStack Router with file-based routing (4 routes: /, /timeline, /tasks, /projects)
- Tailwind CSS 3 + PostCSS with Figma design tokens (sidebar, primary, muted)
- Framer Motion, Lucide React, shadcn/ui utilities (cn, CVA, clsx, twMerge)
- AppShell layout: 240px sidebar with collapse toggle, active route highlighting
- Vite configs use .mts extension to avoid ESM/CJS conflict with electron-forge
- Full package build verified (linux x64)

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

.eslintrc.json

@@ -0,0 +1,16 @@
+{
+  "env": {
+    "browser": true,
+    "es6": true,
+    "node": true
+  },
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/eslint-recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:import/recommended",
+    "plugin:import/electron",
+    "plugin:import/typescript"
+  ],
+  "parser": "@typescript-eslint/parser"
+}